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DRAKENSTEIN MUNICIPALITY

WASTE WATER RISK ABATEMENT PLAN (W2RAP)

REVISION B

FEBRUARY 2013 Prepared by : Prepared for : LYNERS CONSULTING ENGINEERS

DRAKENSTEIN MUNICIPALITY

AND PROJECT MANAGERS P O BOX 1 P O BOX 79 MAIN STREET PAARL MAIN STREET PAARL 7622 7622 TEL : (021) 872 3564 TEL : (021) 807 4500 FAX : (021) 872 0619 FAX : (021) 872 8054

Revision History

Revision No.

Prepared by Description Date

Draft A Lyners Draft of W2RAP 7 October 2011

Draft B Lyners Draft of W2RAP 1 February 2013

Document Acceptance

Action Name Signed Date

Prepared by Lyners

Reviewed by R Brown

Approved by R Brown

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U:\Werke\0800\0828 - Drakenstein W2RAP\Rep\W2RAP revB 2013\0828 W2RAP Report Rev B Feb 2013.docx

Table of Contents

1 INTRODUCTION................................................................................................................................... 1

2 DESCRIPTION OF W2RAP TEAM ....................................................................................................... 1

2.1 Duties of team and commitment ........................................................................................................ 1

3 DESCRIPTION OF VARIOUS WORKS ............................................................................................... 3

3.1 Paarl WWTW ..................................................................................................................................... 3

3.1.1 Catchment ...................................................................................................................................... 3

3.1.2 Collection ....................................................................................................................................... 3

3.1.3 Treatment ....................................................................................................................................... 3

3.2 Wellington WWTW ............................................................................................................................. 4

3.2.1 Catchment ...................................................................................................................................... 4

3.2.2 Collection ....................................................................................................................................... 4

3.2.3 Treatment ....................................................................................................................................... 5

3.3 Pearl Valley WWTW .......................................................................................................................... 5

3.3.1 Catchment ...................................................................................................................................... 5

3.3.2 Collection ....................................................................................................................................... 5

3.3.3 Treatment ....................................................................................................................................... 6

3.4 Saron WWTW .................................................................................................................................... 6

3.4.1 Catchment ...................................................................................................................................... 6

3.4.2 Collection ....................................................................................................................................... 7

3.4.3 Treatment ....................................................................................................................................... 7

3.5 Hermon WWTW ................................................................................................................................. 7

3.5.1 Catchment ...................................................................................................................................... 7

3.5.2 Collection ....................................................................................................................................... 8

3.5.3 Treatment ....................................................................................................................................... 8

3.6 Gouda WWTW ................................................................................................................................... 8

3.6.1 Catchment ...................................................................................................................................... 8

3.6.2 Collection ....................................................................................................................................... 8

3.6.3 Treatment ....................................................................................................................................... 8

4 HAZARD ASSESSMENT ...................................................................................................................... 9

4.1 Risk Matrix used ................................................................................................................................ 9

4.2 Hazard Analysis of works ................................................................................................................ 11

4.3 Paarl WWTW ................................................................................................................................... 11

4.4 Pearl Valley WWTW ........................................................................................................................ 15

4.5 Wellington WWTW ........................................................................................................................... 17

4.6 Hermon WWTW ............................................................................................................................... 21

4.7 Saron WWTW .................................................................................................................................. 22

4.8 Gouda WWTW ................................................................................................................................. 26

5 CONTROL MEASUREMENTS ........................................................................................................... 29

6 MONITORING OF CONTROL MEASURES AND RESPONSE PROTOCOL ................................... 31

6.1 Operational Alert Levels .................................................................................................................. 32

6.2 Verification of functioning of W2RAP ............................................................................................... 32

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7 SUPPORT PROGRAMMES ............................................................................................................... 33

7.1 Process Controller Training Provided .............................................................................................. 33

7.2 Supervisors Forum .......................................................................................................................... 33

7.3 Career Pathing ................................................................................................................................. 33

7.4 Consultant Advisors ......................................................................................................................... 33

8 INCIDENT MANAGEMENT PLAN ...................................................................................................... 33

9 CONCLUSIONS .................................................................................................................................. 36

10 RECOMMENDATIONS ....................................................................................................................... 36

10.1 Risks to be addressed ..................................................................................................................... 36

10.2 Way forward ..................................................................................................................................... 36

ANNEXURES : ANNEXURE A : CATCHMENTS

ANNEXURE B : FLOW DIAGRAMMES

ANNEXURE C : DRAKENSTEIN MUNICIPALITY : WWTW RISK ASSESSMENT

ANNEXURE D : DRAKENSTEIN MUNICIPALITY : WASTE WATER INCIDENT MANAGEMENT PROTOCOL

ANNEXURE E : HIGH AND MEDIUM RISK ITEMS FOR WWTW WITH MITIGATION MEASURES

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1 INTRODUCTION

Drakenstein Municipality currently (year 2013) provides Waste Water Treatment to six (6) communities within it’s municipal boundaries amounting to approximately 240 000 residents. Of the six Waste Water Treatment Works (WWTW), four are activated sludge works and two are evaporation pond systems. Drakenstein Municipality currently experiences challenges with regards to WWTW operation and maintenance which include :

- Aging Infrastructure (Sections of Paarl WWTW were upgraded in the 1960’s)

- Relatively low Operational & Maintenance Budgets for WWTW’s

- Large funding shortfalls for upgrading of existing infrastructure and construction of new infrastructure or technologies.

- Skill shortages in WWTW management and operations

- Large increases in flow volumes due to increasing housing developments; and

- Erratic power supply from national providers.

Given these challenges, it is imperative to follow a risk based management method to risks in the treatment process and identify priority risk areas for inclusion in limited Operational & Maintenance- and Capital upgrading budgets. To this end Drakenstein Municipality has developed a Waste Water Risk Abatement Plan (W

2RAP)

to identify potential risks and mitigation measures for each risk. This document is a living document which will be reviewed and amended constantly as and when the risk situation changes. This document provides an overview of the risks faced by the Drakenstein Municipality and must be considered in conjunction with the other reference documents such as the Green Wastewater Performance Audit Report (November 2012) and the Sewer Master Plan (December 2012).

2 DESCRIPTION OF W

2RAP TEAM

2.1 Duties of team and commitment

The W2RAP team is a multi disciplinary team consisting of team members with intimate knowledge

of the Waste Water Treatment system and the receiving environment. A diagramme showing the composition of this team is shown in figure 2.1 below.

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Figure 2.1 : Diagramme of W

2RAP Team

As the W2RAP is a living document, it is expected that the members of the team provide continual

feedback on the implementation of the system as well as potential improvement. The W

2RAP is a management tool designed to assist policy makers in decision making with regards

to Waste Water Treatment. Drakenstein Municipality owns and manages a total of six (6) WWTW’s and collection systems, namely:

• Paarl Wastewater Treatment and Collection System

• Wellington Wastewater Treatment and Collection System

• Pearl Valley/Val de Vie Wastewater Treatment and Collection System (also known as the Kliprug Wastewater Treatment Plant)

• Saron Wastewater Treatment and Collection System

• Gouda Wastewater Treatment and Collection System

• Hermon Wastewater Treatment and Collection System

Team Leader

Mr R Brown Head of Waste Services Drakenstein Municipality

Compilers

Mr H Mulder (Civil Engineer) and Mr M Filippi (Prof. Civil Engineer and Project Manager)

Private Entities

Berg River Irrigation Board

Information Sources

Mr C Morkel (Supervisor on all Drakenstein WWTW’s)

Various Process controllers for each WWTW

Department of Water Affairs (DWA)

Legislative Bodies

Consultants including WorleyParsons (Green Wastewater Performance Audit), Aurecon and Lyners (Various WWTW’s) AL Abbott Laboratories (Process Auditing) Virtual Consulting Engineers (Saron WWTW) Integral Laboratories (All WWTW’s)

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3 DESCRIPTION OF VARIOUS WORKS 3.1 Paarl WWTW 3.1.1 Catchment

The Paarl WWTW Services a vast section of the Paarl area, from the Bo-Dal Josafat Area to the Paarl South Area, including the areas of Mbekweni and Silvertown to the north. The WWTW is situated next to the Berg River, into which final effluent is discharged. The WWTW is a Class C WWTW under the DWA classifications and currently (2013) has a capacity of 27Mℓ/d, receives and Average Daily Dry Weather Flow (ADDWF) of approximately 22Mℓ/d and is licensed by a water usage permit (No 1222B). A layout of the Paarl WWTW catchment is shown in drawing no 0828/C/002 in Annexure A. The receiving environment is the Berg River. The final effluent must comply with the requirements of the Water Act and for Paarl WWTW these are General Standard. In the near future however the WWTW may need to comply with the Special Standards.

3.1.2 Collection

Influent is conveyed to the Paarl WWTW through various gravity bulk sewers mainly along the Berg River from South to North. The main sewers include the domestic outfall sewer and the industrial outfall sewer. The Bulk Sewer to Southern Paarl currently under construction will serve as a further domestic bulk sewer addressing capacity shortfalls in the existing domestic bulk sewer and providing for future developments in the south of Paarl. Furthermore there are several sewage pumping stations in the catchment that convey sewage via rising mains to the Paarl WWTW which include the following pumping stations shown in table 3.1 below.

Table 3.1 : Sewage Pumping Stations within Paarl

Name of Pumping Station Pumping station to/into

Paarl South Pumping Station No 1 & 2

Existing Domestic Outfall Sewer

Boschenmeer Existing Domestic Outfall Sewer

Roodeberg Existing Domestic Outfall Sewer

Carletta Collector Sewer draining to the Existing Domestic Outfall Sewer

Kaplan Street Collector Sewer draining to the Existing Domestic Outfall Sewer

Dal Josafat Directly to the inlet works of the WWTW

Mbekweni Directly to the inlet works of the WWTW

Silvertown Collection Sewer draining to Mbekweni Pumping Station

Most of the reticulation infrastructure is relatively old, but in good condition. The Asset Management Register of Drakenstein Municipality estimates that approximately 47,6% of the value (useful life) of the sewage network has been consumed. Not withstanding this, the network is continually refurbished/upgraded to replace old infrastructure.

3.1.3 Treatment

The Paarl WWTW comprises a combination of trickling filters (biofilters) and activated sludge processes, with maturation ponds for tertiary treatment. Normally all flow passes through the trickling filter works, after which it is further treated in the activated sludge works. During periods of high flow, excess flow that cannot be accommodated hydraulically in the trickling filter works, then bypasses this section and flows directly to the activated sludge works.

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In 2003, Drakenstein Municipality appointed Ninham Shand (now Aurecon) in association with Lyners to investigate and report on options for upgrading the existing WWTW to provide for nutrient removal, and in particular for phosphate removal (for a maximum ortho-phosphate level of 1 mg/L as PO4). Subsequent to this investigation, Drakenstein Municipality appointed Africon (now Aurecon) to compile a master plan which identified the preferred locations for future WWTW’s in the area. This investigation recommended that the existing Paarl WWTW be developed to a capacity of 35 Mℓ/d. The consulting engineers recommended the treatment of a blend of industrial humus tank effluent and settled and raw domestic sewage in a biological nutrient removal (BNR) activated sludge process. The process was achieved by converting the existing aerated lagoon to a BNR activated sludge system. Upgrading of the aerated lagoon was completed in March 2012.

A flow diagramme of the works is included in Annexure B.

3.2 Wellington WWTW 3.2.1 Catchment

The Wellington WWTW services the entire Wellington area, from the Newton- and Erf 8000 areas in the south to the Pentz Domestic area in the north as well as the Industrial Park Area in the west of Wellington. The WWTW is a Class C WWTW under the DWA classifications and currently has a capacity of 6Mℓ/d with a ADDWF of approximately 5.5Mℓ/d. Upgrading of this WWTW to a capacity of 16 Mℓ/d is currently underway. The WWTW is licensed by a water usage permit (No 918B). A layout of the Wellington WWTW catchment area is shown on drawing no 0828/C/003 in Annexure A. As with the Paarl WWTW, the receiving environment for the effluent from the Wellington WWTW is also the Berg River and the Wellington WWTW most also comply with the General Standard. In future the WWTW may also need to comply with the Special Standard.

3.2.2 Collection

Influent to the Wellington WWTW is from various Sewage Pumping Stations conveying sewage to the WWTW via rising mains. The various pumping stations in the Wellington area are shown in table 3.2 below.

Table 3.2 : Sewage Pumping Station within Wellington


Erf 8000 Newton Sewage Pumping Station

Newton Directly to the WWTW Inlet

Wellington Industries Directly to the WWTW Inlet *(1)

Pentz Street Industrial and Domestic Pumping Stations

Directly to the WWTW Inlet *(1)

Nywerheids Park Directly to the WWTW Inlet *(2)

Kromrivier Collector Sewers draining towards the Pentz Street Domestic Pumping Station

*(1)

These two pumping stations will be consolidated into one large pumping station (Pentz Street Sewage Pumping Station). Construction is estimated to be completed by June 2013.

*(2)

This pumping station was recently upgraded.

Currently the influent to the WWTW is not separately treated with respect to industrial- and domestic influent.

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Some of the pumping stations and rising mains such as the Pentz Street Domestic- and Industrial Pumping Stations are old or at capacity and require replacement or upgrading. However for the most part of the reticulation network is in good condition and have a remaining useful life similar to that of the Paarl. Some re-use of effluent is already implemented with the Wellington Golf Club receiving irrigation water from the works. This is on a relatively small scale and amount. Similarly to Paarl WWTW, it is envisioned that further re-use of effluent for irrigation or large industrial use must occur in future. This process is in the Planning Phase in conjunction with the Paarl WWTW.

3.2.3 Treatment

The Wellington WWTW combines the biological wastewater treatment systems of trickling filters and activated sludge. Raw wastewater (consisting of domestic sewage and industrial effluent) flows through an inlet works to two primary settling tanks and then to five trickling filters (biofilters) of which two are large biofilters supplemented by three smaller biofilters. The effluent from the biofilters is settled in two humus tanks and the settled water is then pumped to the activated sludge bioreactor and a secondary settling tank. The final effluent is chlorinated before receiving tertiary treatment in five maturation ponds in series. The effluent from the last maturation pond discharges to a natural stream which flows to the Berg River. Waste sludge is either treated in two anaerobic digesters and then in sludge drying beds, or in two sludge lagoons. The WWTW is in need of upgrading and extension of the treatment capacity. Aurecon in association with Lyners was appointed in 2010 to investigate options for the required upgrading and extensions. The project is currently (2013) in the in the Planning and Environmental Impact assessment Phase.

A flow diagramme of the works is included in Annexure B.

3.3 Pearl Valley WWTW 3.3.1 Catchment

The Pearl Valley WWTW services the Pearl Valley Golf Estate and the Val-de-Vie Developments to the south of Paarl. The WWTW is a Class D works under the DWA classifications and currently has a capacity of 1Mℓ/d with a ADDWF of approximately 0.2Mℓ/d. This WWTW is licensed under a General Authorization (Ref 16/2/7/G100/A/8). A layout of the Pearl Valley WWTW catchment area is included in Annexure A drawing no 0828/C/001. Again the receiving environment for final effluent is the Berg River and the WWTW must also currently comply with the General Standard. It may also have to comply with the Special Standard in future.

3.3.2 Collection

Influent to this WWTW is domestic in nature and is conveyed to the WWTW via various Sewage Pumping Stations and Rising mains which are shown below in table 3.3.

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Table 3.3 : Sewage Pumping Stations in the Pearl Valley WWTW Catchment


Pearl Valley Directly to the WWTW Inlet

Val-de-Vie 3 Directly to the WWTW Inlet

Val-de-Vie 1,2,5 and 6- and the Guardhouse Pumping Stations

Collector sewers ultimately draining to Val-de-Vie 3 Pumping Station

These pumping stations and reticulation networks are relatively new and in good condition. 3.3.3 Treatment

The Pearl Valley WWTW’s consists of two nearly identical activated sludge modules. The first module (“old section”) was provided to treat the wastewater from the Pearl Valley Golf Estate, while the second module (“new section”) was added later to treat wastewater from the more recently established Val-de-Vie Development. Raw domestic sewage from the two private developments both enter the WWTWs in an inflow sump at the head of the works, from where it flows through a communal inlet works (hand raked screen; grit channels) to two activated sludge reactors. The reactors have been designed for biological nutrient removal and therefore include anoxic zones for denitrification. After the removal of the biomass (sludge) in the secondary settling tanks, the settled water is chlorinated and then polished in large maturation ponds before discharging to a natural water course leading to the Berg River. Waste sludge is disposed of in sludge drying beds. However, the system currently operates on a low MLSS, resulting in low waste sludge volumes to be disposed of. A mechanical sludge dewatering facility has also been provided at the WWTW, but to date this has not been used. A flow diagramme of the works is included in Annexure B.

3.4 Saron WWTW 3.4.1 Catchment

The Saron WWTW services the rural town of Saron north of Gouda. The WWTW is a Class E works under the DWA classification and currently has a capacity of 1Mℓ/d with a ADDWF of approximately 0.8Mℓ/d. The WWTW is licensed by a General Authorization. A conditional assessment of the works was undertaken which recommended upgrading of various structures at the works which include construction of a new activated sludge reactor. The first phase of the upgrading project is currently in the construction phase with a second phase currently (2013) in the planning and EIA phase. A layout of the Saron WWTW catchment is included in drawing no 0828/C/006 in Annexure A. The receiving environment for this works is the Klein Berg River which ultimately drains to the Berg River. This works is also subject to the General Standard for effluent and may in future be subject to the Special Standard.

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3.4.2 Collection

Influent to this WWTW is domestic in nature and is conveyed to the WWTW from a Sewage Pumping Station which was recently upgraded. There are only two Sewage Pumping Stations in Saron which operate as shown in the table 3.4 below.

Tabel 3.4 : Sewage pumping station in Saron.


Saron 1 Collector sewer draining towards Pumping Station

Saron 2 Directly into the Saron WWTW inlet works*

* Recently upgraded

Although most of the reticulation network is old it is still in good condition. As stated above the Saron 2 Sewage Pumping Station and Rising main was recently upgraded. The conditional assessment of the works found that the structures in the WWTW with the exception of the Secondary Settling tank (Clarifier) and the chlorination channel were not in a good condition. Therefore refurbishment and upgrading of the works was proposed.

3.4.3 Treatment

The Saron WWTW is also an activated sludge treatment works, but unlike the Paarl and Wellington WWTW, it is a relatively small plant with open ponds converted to an activated sludge reactor, with an aerobic zone and an anoxic zone. Raw sewage from Saron enters the works via the inlet works (hand raked screen followed by grit channels) to the anoxic zone of the activated sludge reactor. It overflows to the aeration section (with floating aerators) and then to a secondary settling tank. Return activated sludge is recycled to the anoxic zone, and waste activated sludge discharged to the sludge drying beds from time to time (daily sludge wasting is recommended). The settled wastewater from the secondary settling tank is firstly disinfected through chlorination and then normally flows to a series of maturation ponds, located some distance from the works. These ponds have become redundant and are in the process of being upgraded. As stated above this WWTW must be upgraded and refurbished. A flow diagramme of the works is included in Annexure B.

3.5 Hermon WWTW 3.5.1 Catchment

The Hermon WWTW services the small rural town of Hermon which is only partly serviced by gravity sewers with a Sewage Pumping Station. The other section of Hermon has conservancy tanks which are emptied by tanker trucks at regular intervals and the sewage from the tankers is then taken to the WWTW. The WWTW is a Class E works, under the DWA classification and currently has a capacity of 0.3Mℓ/d and a ADDWF of approximately 0.1Mℓ/d. This plant operates under a General Authorization from DWA (Ref 16/2/7/G/10F). A layout of the Hermon WWTW catchment is shown on drawing no 0828/C/004 in Annexure A. As the works is and evaporation pond system there is no effluent outflow.

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3.5.2 Collection

As stated above Hermon is only partially serviced with gravity sewers draining to the Hermon Sewage Pumping Station which conveys sewage to the WWTW. The other section of Hermon has conservancy tanks which are emptied by tanker truck at regular intervals and taken to the WWTW.

It is envisioned that in future the conservancy tanks will be made redundant by the installation of gravity sewers and a new Sewage Pumping Station.

The existing reticulation system is relatively old but still in good condition.

3.5.3 Treatment

The treatment system for Hermon is an evaporation pond system, consisting of two large, unlined evaporation ponds. Provision has been made for using the pond overflow for irrigation purposes (an irrigation pump has been installed for this purpose), but currently both the ponds are empty due to evaporation and possible seepage.

A flow diagramme of the works is included in Annexure A.

3.6 Gouda WWTW 3.6.1 Catchment

The Gouda WWTW services the rural town of Gouda to the north of Hermon. The WWTW is a Class E works under the DWA classification currently having a capacity of 0.64Mℓ/d and a ADDWF of approximately 0.4Mℓ/d. The works is currently licensed by a water use permit (No 1331B). As this works is also an evaporation pond system there is no effluent outflow. A layout of the Gouda WWTW catchment is included in Annexure A drawing no 0828/C/005.

3.6.2 Collection

In the past Gouda was divided into two sections Gouda north (north of the R45) was serviced by gravity sewers draining towards the Gouda Sewage Pumping Station which conveyed sewage to the WWTW. The Gouda South section was serviced by conservancy tanks with tanker trucks removing sewage to the WWTW regularly. Construction of a gravity sewer reticulation network for the Gouda South section is currently underway. This new reticulation network will drain to the Gouda North network, onto the Gouda Sewage Pumping Station and ultimately the Gouda WWTW. The Gouda North reticulation network is relatively old but still in good condition. A new Gouda Sewage Pumping Station and reticulation network for Gouda South was recently completed and are at the start of their service life.

3.6.3 Treatment

The Gouda WWTW is a waste stabilisation pond system (evaporation ponds) consisting of two primary ponds, followed by four secondary oxidation ponds. The final effluent overflowing from the last pond is used as irrigation water on the rugby field in town. Upgrading and rehabilitation of the pond system was recently completed, which included upgrading of the pump station in the town. A flow diagramme of the works is included in Annexure B.

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4 HAZARD ASSESSMENT

In 2011 DWA promoted the use of a W2RAP to identify risks at WWTW’s in detail and to this end all

of Drakenstein Municipality’s WWTW were analysed and a W2RAP drafted.

The W

2RAP is based on a risk factor which is obtained as a product of the perceived probability of

occurrence and the significance or consequence. A risk matrix must be set up to classify risks as low, medium or high.

4.1 Risk Matrix used

As stated above the risk factor is calculated as follows :

Risk factor = Probability of occurrence X significance or consequence

Based on this equation the following risk matrix and factors were used as shown in Figure 4.1 below.

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Figure 4.1 : Risk Matrix used for Hazard Assessment

Min Risk

2 7 8 13 14 19 20 24 25 26 30

Max Risk

Low Risk 2 to 13 Medium Risk 14 to 25 High Risk 25 to 30

Probability Score (Probability of Occurrence)

Severity Score

(Consequence of failure)

1 Rare

(1 in 5 years)

2 Insignificant (No Impact)

2 Unlikely

(once per annum)

3 Minor

(Minor Impact to a large population)

3 Moderately Likely (once per month)

4 Moderate

(Moderate Impact to a large population)

4 Likely

(once per week)

5 Major

(Population exposed to significant illness)

5 Almost Certain

(Once a day or permanent feature)

6 Catastrophic

(Death expected from exposure)

Risk Matrix

Severity

Risk Matrix

Severity

2 3 4 5 6

2 3 4 5 6

Probability

1 2 3 4 5 6

Probability

1 2 3 4 5 6

2 4 6 8 10 12

2 4 6 8 10 12

3 6 9 12 15 18

3 6 9 12 15 18

4 8 12 16 20 24

4 8 12 16 20 24

5 10 15 20 25 30

5 10 15 20 25 30

Based on this risk matrix all risks are classified on their probability (score between 2 and 5) and severity (score between 2 and 6) and ranked as Low, Medium or High.

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This formed the basis for the Hazard Assessment undertaken for each WWTW below.

4.2 Hazard Analysis of works

A Hazard Assessment was undertaken for each WWTW taking into account, among others, the following.

- The catchment - Surface water - Ground water - Collector systems - Treatment - Other factors

The risk analysis further also differentiated between four district risk categories for each section of the works namely :

• Electrical failure (including motor failure, power failure, etc.)

• Mechanical failure (eg gearboxes, sluices, gate valves, pumps, etc.)

• Structural failure (eg structures needing replacement/refurbishment or upgrading)

• Process failure (non-compliance with DWA Standards, Operational monitoring etc.)

Risk scores were allocated based mostly on the effect on the receiving environment and the end user. The risk assessment is also only a high level risk assessment and may be elaborated on in future revisions of this document.

4.3 Paarl WWTW The full risk matrix for the Paarl WWTW is included in Annexure C. The risk classified as Medium or High Risks are shown in table 4.1 below.

Table 4.1 : Paarl WWTW : Medium to High Risk Items Item no

System Hazard/Risk Description

Could this issue result in a risk?

Likelihood Consequence Inherent Risk Score (before

consideration of any controls)

Process Failure

11 Domestic Pumping

Station Influent compliance Y 4 5 20 Medium

12 Domestic Pumping

Station Design Capacity Y 4 5 20 Medium

Mechanical Failure

20 Industrial Inlet

Works Hand Raked Screens Y 5 3 15 Medium

Process Failure

21 Industrial Inlet

Works Influent compliance Y 4 5 20 Medium

Process Failure

27 Flocculator Operational

Monitoring Y 4 4 16 Medium

Electrical Failure

28 Flocculator Power failure to

bridge Y 3 5 15 Medium

Structural Failure

30 Domestic

splitterbox Tower Y 3 5 15 Medium

Process Failure

33 Domestic PST's Operational


Structural Failure

38 Biofilters Old Biofilter walls Y 5 5 25 High

Process Failure

39 Biofilters Operational


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Item no





Process Failure

43 Humus Tanks Operational


Process Failure

60 Aerobic Zone Operational


Process Failure

66 Clarifier Operational


Structural Failure

67 New Clarifier Clarifier Structure too

low Y 4 4 16 Medium

Structural Failure

77 Tanks Dome structure on

Tanks Y 5 5 25 High

Structural Failure

78 Digester Structure of digester Y 5 5 25 High

General

80 Digester Deep Structure Y 5 5 25 High

General

81 Incinerators Incinerators very old Y 4 4 16 Medium

Process Failure

84 Maturation Ponds Operational


Electrical Failure

85 Chlorination Store

Room

Warning Lights

outside building Y 4 6 24 Medium


Room Dosing Electronics Y 4 6 24 Medium

Process Failure

89 Chlorination

Channel

Compliance

Monitoring Y 5 5 25 High

Electrical Failure

91 Transformer Transformers on site

(4 No) Y 5 5 25 High

92 Genset Switch Over Board Y 4 5 20 Medium

General

94 General Site Lighting Y 3 5 15 Medium

95 General Telemetry at works Y 5 4 20 Medium

The risks mainly include operational- and compliance monitoring, replacement or upgrading of structures and dangerous installations such as chlorination storage. These risk are or can be mitigated by employing risk mitigation measures which are shown in table 4.2 below.

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Table 4.2 : Paarl WWTW : Risk Mitigation Measures for Medium to High Risks

Item no


Inherent Risk Score (before consideration

of any controls) Existing controls

Control Effectiveness

(%)

Residual Risk Score

Comment Recommended mitigation/

improvement plan

Process Failure

11 Domestic Pumping

Station

Influent

compliance 20 Medium

Operational Monitoring

through on site Mini Lab.,

weekly verification at Paarl

WWTW lab. and Monthly

Audit by Independent Lab.

(A.L. Abbott)

80 4 Low Operational monitoring is to occur to

operational monitoring alert level

Ensure monitoring occurs as

scheduled

12 Domestic Pumping

Station Design Capacity 20 Medium - 0 20 Medium

The existing Pumping Station has a

lower capacity than newly

constructed sewer

Investigate New pumping station

with higher capacity

Mechanical

Failure

20 Industrial Inlet

Works

Hand Raked

Screens 15 Medium

Permanent Cleaning of Screen

throughout the day 70 4.5 Low

Permanently posted staff clean hand

raked screen

Investigate installation of

mechanical screens in future

Process Failure

21 Industrial Inlet

Works

Influent







(A.L. Abbott)

80 4 Low Operational monitoring is to occur to

operational monitoring alert level


scheduled

Process Failure

27 Flocculator Operational

Monitoring 16 Medium






(A.L. Abbott)

80 3.2 Low

Operational monitoring to occur to

alert levels with corrective actions as

per Alert Level

Ensure Monitoring occurs as

scheduled and incident

management protocol is

followed

Electrical Failure

28 Flocculator Power failure to

bridge 15 Medium - 0 15 Medium

No power to the bridge at present

and process is being affected

Power to be provided to bridge

immediately

Structural

Failure

30 Domestic

splitterbox Tower 15 Medium - 0 15 Medium Tower must be investigated

Investigate structure of tower

and gratings

Process Failure

33 Domestic PST's Operational







(A.L. Abbott)

80 3.2 Low Operational monitoring needed with

Actions as per Alert Level Follow Alert Level actions

Structural

Failure

38 Biofilters Old Biofilter

walls 25 High Structure strapping 10 22.5 Medium

currently strapping is used to

reinforce broken brickwork outer

walls

Refurbish walls as part of future

upgrade

Process Failure

39 Biofilters Operational







(A.L. Abbott)

80 3.2 Low



per Alert Level




followed

Process Failure

43 Humus Tanks Operational







(A.L. Abbott)

80 3.2 Low



per Alert Level




followed

Process Failure








(A.L. Abbott)

80 4 Low Operational Monitoring to determine

sludge wasting

Operational Monitoring as

scheduled with process

adjustments at alert levels as

necessary

Process Failure








(A.L. Abbott)

80 4 Low



per Alert Level




followed

Structural

Failure

67 New Clarifier

Clarifier

Structure too

low

16 Medium - 0 16 Medium

The clarifier structure was

constructed low in the ground and

the possibility exists for someone to

fall into the clarifier as there is no

handrail around the clarifier

Construct handrail around

clarifier with apron

Structural

Failure

77 Tanks Dome structure

on Tanks 25 High

Signage, Gas traps and 24h

monitoring 80 5 Low

Inspection of the dome must

occur at regular interval as

determined by a structural

Engineer

Structural

Failure

78 Digester Structure of

digester 25 High

Signage, Gas traps and 24h

monitoring 80 5 Low




Engineer

General

80 Digester Deep Structure 25 High - 0 25 High No life buoy or safety ropes in a very

deep structure

Provide life buoys and safety

ropes for structure

General

81 Incinerators Incinerators

very old 16 Medium - 0 16 Medium

The incinerators are very old and

parts have become hard to source

Upgrade of the incinerators must

be investigated as part of future

upgrade

14


Item no



of any controls) Existing controls


(%)

Residual Risk Score

Comment Recommended mitigation/

improvement plan

Process Failure

84 Maturation Ponds Operational







(A.L. Abbott)

80 4 Low



per Alert Level




followed

Electrical Failure


Room

Warning Lights

outside building 24 Medium

Warning lights checked daily,

with Reactive Maintenance

and Standby Generator on

Site

100 0 None Weekly inspection of

Component


Room

Dosing

Electronics 24 Medium

Reactive Maintenance and

Standby Generator on Site 80 4.8 Low

Weekly inspection of

Component

Process Failure

89 Chlorination

Channel

Compliance

Monitoring 25 High

24h Compliance Monitoring

with on site lab. Newly

refurbished

90 2.5 Low

Compliance Monitoring to occur to


per Alert Level




followed

Electrical Failure

91 Transformer Transformers on

site (4 No) 25 High

Operation and Maintenance

from Drakenstein Electrical

Department

0 25 High

Drakenstein Electrical Department is

laboring under capacity constraints

and maintenance cannot always be

effected in time

Maintenance schedule for all

transformers which MUST be

adhered to and additional

staffing in the Electrical

Department

92 Genset Switch Over

Board 20 Medium - 0 20 Medium

The existing switch board is old and is

in need of upgrading with new

switchgear, etc.

Investigate upgrading of switch

board as part of future upgrade

of works

General

94 General Site Lighting 15 Medium Existing high mast lighting 50 7.5 Low Investigate additional high mast

lighting when required

95 General Telemetry at

works 20 Medium 0 20 Medium

Contractor appointed to upgrade

entire telemetry network

Monitor contractor performance

and telemetry performance after

commissioning

15


If these mitigation measures are implemented the overall risk classification of the works may be regarded as low. 4.4 Pearl Valley WWTW

The full risk matrix for the Pearl Valley WWTW is included in Annexure C. The risk classified as Medium or High Risks are shown in table 4.3 below.

Table 4.3 : Pearl Valley WWTW : Medium to High Risk Items Item no





Electrical Failure


Room

Warning Lights

outside building Y 4 6 24 Medium


Room Dosing Electronics Y 4 6 24 Medium

Process Failure

38 Maturation Ponds Compliance

Monitoring Y 5 5 25 High

Electrical Failure

42 Pumping Station Power failure Y 5 4 20 Medium

43 Pumping Station Telemetry Y 4 5 20 Medium

Mechanical Failure

44 Sludge Drying

Beds Drainage Pump Y 4 4 16 Medium

General

45 General Security at works Y 4 6 24 Medium

46 General Office Facilities Y 5 6 30 High

The risks mainly include operational- and compliance monitoring, upgrading of structures and dangerous installations such as chlorination storage.

These risk are or can be mitigated by employing risk mitigation measures which are shown in table

4.4 below. Table 4.4 : Pearl Valley WWTW : Risk Mitigation Measures for Medium to High Risks

Item no



of any controls)

Existing controls


(%)

Residual Risk Score

Comment

Recommended mitigation/

improvement plan

Electrical

Failure

33 Chlorination

Store Room

Warning

Lights

outside

building

24 Medium

Reactive

Maintenance

and Standby

Generator on

Site

80 4.8 Low

An audit has

been

performed and

corrective

measures have

been

identified.

Weekly

inspection of

Component

34 Chlorination

Store Room

Dosing

Electronics 24 Medium

Reactive

Maintenance

and Standby

Generator on

Site

80 4.8 Low

An audit has

been

performed and

corrective

measures have

been

identified.

Weekly

inspection of

Component

Process

Failure

16


Item no



of any controls)

Existing controls


(%)

Residual Risk Score

Comment


improvement plan

38 Maturation

Ponds

Compliance

Monitoring 25 High

Compliance

Monitoring

through on site

Mini Lab.,

weekly

verification at

Paarl WWTW

lab. and

Monthly Audit

by Independent

Lab. (A.L.

Abbott) and

Maturation

Pond

Maintenance

80 5 Low

Compliance

monitoring to

occur to alert

levels with

corrective

actions as per

Alert Level,

Algal problems

occurred in

retention pond

and retention

time was

reduced,

however

sediment

transport

remains

problematic

Ensure

Monitoring

occurs as

scheduled and

incident

management

protocol is

followed

Electrical

Failure

42 Pumping

Station

Power

failure 20 Medium

Standby

generator on

site & Overflow

pond

90 2 Low -

Pro-Active

Maintenance

Required &

servicing of

standby

generator

required

43 Pumping

Station Telemetry 20 Medium - 0 20 Medium

Contractor

appointed to

upgrade entire

telemetry

network

Monitor

contractor

performance

and telemetry

performance

after

commissioning

Mechanical

Failure

44 Sludge

Drying Beds

Drainage

Pump 16 Medium

Reactive

Maintenance 100 0 None

New Pump

Currently

sourced

Monitor

supplier

performance

and pump

performance

after

commissioning

General

45 General Security at

works 24 Medium - 0 24 Medium

No Security on

site

Provide security

guard and

facilities as part

of the future

upgrade

46 General Office

Facilities 30 High - 0 30 High

No office on

site. Non-

Compliance

with OSH Act

Provide office

facilities as part

of the future

upgrade

17


If these mitigation measures are implemented the overall risk classification of the works may be regarded as low 4.5 Wellington WWTW The full risk matrix for the Wellington WWTW is included in Annexure C. The risk classified as Medium or High Risks are shown in table 4.5 below.

Table 4.5 : Wellington WWTW : Medium to High Risk Items Item no

System Hazard/Risk Description Could this issue result in a risk?



Electrical Failure

1 Pumping Station Power failure Y 5 5 25 High

Process Failure

2 Pumping Station Flow meter Y 3 5 15 Medium

Mechanical Failure

3 Pumping Station Screening of Sewage Y 4 5 20 Medium

General

6 Pumping Station No permanent

supervision Y 5 5 25 High

General

11 Pumping Station Security Y 5 5 25 High

General

12 Pumping Station Design Capacity

Exceedance Y 3 5 15 Medium

Mechanical Failure

14 Pumping Station Screening of Sewage Y 3 5 15 Medium

General

17 Pumping Station Security Y 5 5 25 High

18 Pumping Station Telemetry at pumping

Station Y 3 5 15 Medium

General

21 General Plant Design Capacity

Exceedance Y 5 5 25 High

Electrical Failure

22 Inlet Works Power failure Y 5 5 25 High

Process Failure

26 Inlet Works Influent compliance Y 4 5 20 Medium

Process Failure

31 PST's Operational Monitoring Y 4 4 16 Medium

Process Failure

37 Biofilters Operational Monitoring Y 4 4 16 Medium

Process Failure

43 Humus Tanks Operational Monitoring Y 4 4 16 Medium

Process Failure

55 Aerobic Zone Operational Monitoring Y 4 5 20 Medium

Process Failure

59 Clarifier Operational Monitoring Y 4 5 20 Medium

Electrical Failure


Room

Warning Lights outside

building Y 5 5 25 High


Room Dosing Electronics Y 5 5 25 High

Process Failure

70 Maturation Ponds Compliance Monitoring Y 5 5 25 High

General

71 Sludge Drying

Beds

Design Capacity

Exceedance Y 5 5 25 High

General

72 Digester No Gas Tank Y 4 5 20 Medium

General

73 Incinerator No incinerator on site

for screenings Y 4 5 20 Medium

18


Item no




General

74 Personnel

Facilities Offices Y 4 5 20 Medium



77 General Security Y 5 5 25 High

78 General Signage Y 5 5 25 High

The risks mainly include operational- and compliance monitoring, upgrading of structures, inadequate capacity, no standby electricity generation and dangerous installations such as chlorination storage. These risk are or can be mitigated by employing risk mitigation measures which are shown in table

4.6 below.

19


Table 4.6 : Wellington WWTW : Risk Mitigation Measures for Medium to High Risks

Item no


Inherent Risk Score (before consideration of any controls)

Existing controls Control

Effectiveness (%) Residual Risk

Score Comment Recommended mitigation/ improvement plan

Electrical Failure

1 Pumping Station Power failure 25 High - 0 25 High No Standby Generator on site, Urgently required as this is the closest

pumping station to the Berg River

Process Failure

2 Pumping Station Flow meter 15 Medium - 0 15 Medium Flow meter has not been commissioned

Mechanical Failure

3 Pumping Station Screening of Sewage 20 Medium Basket screen, inspected daily according to pumping station checklist 90 2 Low -

General

6 Pumping Station No permanent

supervision 25 High Daily inspections only 0 25 High Supervision required as pumping station is closest to Berg River

General

11 Pumping Station Security 25 High 3m high wall with barbed wire, fencing, security lights and Armed response 80 5 Low High vandalism rate at this pumping station forced extreme security

measures

General

12 Pumping Station Design Capacity

Exceedance 15 Medium - 0 15 Medium Capacity problems observed in past

Mechanical Failure

14 Pumping Station Screening of Sewage 15 Medium - 0 15 Medium Contract has been issued for provision of a mechanical screen

General

17 Pumping Station Security 25 High Broken fencing and Armed response 25 18.75 Medium High vandalism rate at this pumping station requires security measures

18 Pumping Station Telemetry at pumping

Station 15 Medium - 0 15 Medium

Telemetry required as pumping station is closest to Berg River,

Contractor appointed to upgrade entire telemetry network

General

21 General Plant Design Capacity

Exceedance 25 High 0 25 High

Upgrading of Plant Required, All flows pumped to WWTW therefor also

may need a balancing dam

Electrical Failure

22 Inlet Works Power failure 25 High No Standby Generator on site - 0 25 High No Standby Generator on Site

Process Failure

26 Inlet Works Influent compliance 20 Medium Operational Monitoring through on site Mini Lab., weekly verification at Paarl

WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) - 80 4 Low Operational monitoring is to occur to operational monitoring alert level

Process Failure

31 PST's Operational Monitoring 16 Medium Operational Monitoring through on site Mini Lab., weekly verification at Paarl

WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) - 80 3.2 Low Operational monitoring needed with Actions as per Alert Level

Process Failure

37 Biofilters Operational Monitoring 16 Medium Operational Monitoring through on site Mini Lab., weekly verification at Paarl

WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) 80 3.2 Low

Operational monitoring to occur to alert levels with corrective actions

as per Alert Level

Process Failure

43 Humus Tanks Operational Monitoring 16 Medium Operational Monitoring through on site Mini Lab., weekly verification at Paarl

WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) 80 3.2 Low


as per Alert Level

Process Failure

55 Aerobic Zone Operational Monitoring 20 Medium Operational Monitoring through on site Mini Lab., weekly verification at Paarl

WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) 80 4 Low Operational Monitoring to determine sludge wasting

Process Failure

59 Clarifier Operational Monitoring 20 Medium Operational Monitoring through on site Mini Lab., weekly verification at Paarl

WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) 80 4 Low


as per Alert Level

Electrical Failure


Room

Warning Lights outside

building 25 High

Reactive Maintenance and No Standby Generator on Site, Inspection completed

and Certificate for compliance obtained 90 2.5 Low A Standby Generator on site is imperative


Room Dosing Electronics 25 High

Reactive Maintenance and No Standby Generator on Site, Inspection completed

and Certificate for compliance obtained 90 2.5 Low A Standby Generator on site is imperative

Process Failure

70 Maturation Ponds Compliance Monitoring 25 High Compliance Monitoring through on site Mini Lab., weekly verification at Paarl

WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) 80 5 Low

Compliance monitoring to occur to alert levels with corrective actions as

per Alert Level

General

71 Sludge Drying

Beds

Design Capacity

Exceedance 25 High - 0 25 High 2 Waste ponds, Large Sludge Volume coming into works.

General

72 Digester No Gas Tank 20 Medium - 0 20 Medium The plant has Gas Digesters but no gas tank. A waste to energy project

has been initiated which could utilize the gas

General

73 Incinerator No incinerator on site for

screenings 20 Medium Screenings conveyed to Paarl WWTW for Incineration 50 10 Low -

20


Item no






General

74 Personnel

Facilities Offices 20 Medium Some office space provided with limited ablution facilities 10 18 Medium Existing facilities do not comply with OSH Act

75 General Telemetry at works 20 Medium 0 20 Medium Contractor appointed to upgrade entire telemetry network

76 General Site Lighting 20 Medium Existing Lighting on site 50 10 Low Site lighting may be insufficient

77 General Security 25 High Existing Fence 25 18.75 Medium Contract for a new security fence has been issued and is underway

78 General Signage 25 High - 0 25 High Signage is required on site to comply with various statutory regulations

including the OSH Act

If these mitigation measures are implemented the overall risk classification of the works may be regarded as low

21


4.6 Hermon WWTW

The full risk matrix for the Hermon WWTW is included in Annexure C.

The risk classified as Medium or High Risks are shown in table 4.7 below

Table 4.7 : Hermon WWTW : Medium to High Risk Items

Item no




Process Failure

1 Inlet Influent compliance Y 4 5 20 Medium

Process Failure

6 Evaporation

pond 3

Operational


7 Evaporation

Ponds

Ground Water

Monitoring Wells Y 4 5 20 Medium

Structural Failure

8 Sump Structure Sump Structure Size Y 3 5 15 Medium

Mechanical Failure

9 Pumps Pump Failure Y 3 5 15 Medium

Electrical Failure

10 Pumps No Standby Power Y 5 5 25 High

General

11 General Telemetry at Pumping

Station Y 5 4 20 Medium

The risks mainly consist only of operational- and compliance monitoring as the ponds are oxidation ponds and do not have any mechanical equipment. These risk are or can be mitigated by employing risk mitigation measures which are shown in table

4.8 below. Table 4.8 : Hermon WWTW : Risk Mitigation Measures for Medium to High Risks

Item no



of any controls)

Existing controls


(%)

Residual Risk Score

Comment


improvement plan

Process

Failure

1 Inlet Influent


Operational

monitoring

i.e.

Laboratory

testing

80 4 Low

Operational

monitoring is

to occur to

operational

monitoring

alert level

Ensure

monitoring

occurs as

scheduled

Process

Failure

6 Evaporation

pond 3

Operational


Operational

Monitoring

weekly

sampling with

monthly

audits by

independent

lab. (A.L.

Abbott)

90 2 Low

Operational

monitoring to

occur to alert

levels with

corrective

actions as per

Alert Level

Ensure

Monitoring

occurs as

scheduled and

incident

management

protocol is

followed,

Investigate need

for Mini Lab. On

site

7 Evaporation

Ponds

Ground

Water

Monitoring

Wells

20 Medium

Operational

Monitoring

weekly

sampling with

monthly

audits by

independent

lab. (A.L.

Abbott)

90 2 Low

Operational

monitoring to

occur to alert

levels with

corrective

actions as per

Alert Level

Ensure

Monitoring

occurs as

scheduled and

incident

management

protocol is

followed

22


Item no



of any controls)

Existing controls


(%)

Residual Risk Score

Comment


improvement plan

Structural

Failure

8 Sump

Structure

Sump

Structure

Size

15 Medium

Daily

inspection of

sump

according to

Pumping

Station

checklist

25 11.25 Low

Current sump

structure to

large and has

overflow

walls and no

Mechanical

screen.

Screenings

accumulate in

first chamber

and must be

manually

removed

Investigate

upgrade of

pumping station

and installation

of Mechanical

Screen

Mechanical

Failure

9 Pumps Pump

Failure 15 Medium

Reactive

maintenance

with 24h turn

around time

50 7.5 Low

Pumps may

experience

problems due

to screenings

clogging the

pumps

In the interm

continue daily

inspections and

Investigate

upgrade of

pumping station

and installation

of Mechanical

Screen in future

Electrical

Failure

10 Pumps No Standby

Power 25 High - 0 25 High

At the

moment no

Standby

Power at the

pumping

station

Investigate

supply of

standby power

generator at

pumping station

General

11 General

Telemetry

at Pumping

Station

20 Medium 0 20 Medium

Contractor

appointed to

upgrade

entire

telemetry

network

Monitor

contractor

performance

and telemetry

performance

after

commissioning


4.7 Saron WWTW The full risk matrix for the Saron WWTW is included in Annexure C.

The risk classified as Medium or High Risks are shown in table 4.9 below

Table 4.9 : Saron WWTW : Medium to High Risk Items

Item no





Electrical Failure

1 Inlet Works Power failure Y 5 5 25 High

Mechanical Failure

4 Inlet Works Hand Raked Screens Y 5 3 15 Medium

Process Failure


7 Inlet Works Design Capacity N 4 5 20 Medium

Structural Failure

8 Inlet Works Inlet Works Structure Y 3 5 15 Medium

Electrical Failure

9 Anaerobic Zone Mixer Motors Y 4 4 16 Medium

23


Item no





Mechanical Failure

10 Anaerobic Zone Mixer Gearbox Y 4 4 16 Medium

Structural Failure

11 Anaerobic Zone Zone Structure Y 4 4 16 Medium

Electrical Failure

12 Aerobic Zone Aerator Motors Y 4 4 16 Medium

Mechanical Failure

13 Aerobic Zone Aerator Gearbox Y 4 4 16 Medium

Process Failure



Structural Failure

17 Clarifier Clarifier Structure Y 3 5 15 Medium

Process Failure



Mechanical Failure

20 Pumping Station Pumps Y 5 5 25 High

Electrical Failure


Room

Warning Lights

outside building Y 5 5 25 High


Room Dosing Electronics Y 5 5 25 High

Structural Failure


Room Store Room Structure Y 5 5 25 High

Structural Failure

25 Maturation Ponds Structures across river Y 4 4 16 Medium

Process Failure

26 Maturation Ponds Compliance


Structural Failure

27 Sludge Drying

Beds Bed Structures Y 4 6 24 Medium

Process Failure

28 Sludge Drying

Beds Filter Medium Y 5 3 15 Medium

General


30 General Security Guard at

works Y 5 4 20 Medium


The risks mainly include operational- and compliance monitoring, upgrading of structures, inadequate capacity, no standby electricity generation and dangerous installations such as chlorination storage. As stated earlier in the document Saron WWTW required upgrading and it is therefore expected to identify so many risks These risks however, can be mitigated by employing risk mitigation measures which are shown in table 4.10 below.

24


Table 4.10 : Saron WWTW : Risk Mitigation Measures for Medium to High Risks Item no






Electrical Failure

1 Inlet Works Power failure 25 High No Standby generator on site 0 25 High No Standby Generator on site Install Standby Generator as part of WWTW upgrade.

Contractor appointed and supply of generator imminent

Mechanical Failure

4 Inlet Works Hand Raked

Screens 15 Medium Permanent Cleaning of Screen throughout the day 70 4.5 Low

Permanently posted staff clean hand raked screen and a new

Mechanical screen will be provided at the Saron Sewage pumping

station in new contract

Monitor screenings amount after commissioning of

mechanical screen at Saron Sewage pumping station

Process Failure

6 Inlet Works Influent


Operational Monitoring through on site Mini Lab., weekly

verification at Paarl WWTW lab. and Monthly Audit by

Independent Lab. (A.L. Abbott)

90 2 Low Operational monitoring is to occur to operational monitoring alert

level Ensure monitoring occurs as scheduled

7 Inlet Works Design Capacity 20 Medium 0 20 Medium Upgrade needed of inlet works Upgrade inlet Works as part of WWTW upgrade

Structural Failure

8 Inlet Works Inlet Works

Structure 15 Medium Inspection of Structure 0 15 Medium Upgrade needed of inlet works Upgrade inlet Works as part of WWTW upgrade

Electrical Failure

9 Anaerobic Zone Mixer Motors 16 Medium Reactive Maintenance 90 1.6 None Reactive maintenance at the present with 24h turn around time Replaced Mixer and now Pro-Active Maintenance and

Servicing

Mechanical Failure

10 Anaerobic Zone Mixer Gearbox 16 Medium Reactive Maintenance 90 1.6 None Reactive maintenance at the present with 24h turn around time Replaced Mixer and now Pro-Active Maintenance and

Servicing

Structural Failure

11 Anaerobic Zone Zone Structure 16 Medium 0 16 Medium New Reactor must be constructed as part of WWTW upgrade Construct new Reactor as part of WWTW upgrade

Electrical Failure

12 Aerobic Zone Aerator Motors 16 Medium Reactive Maintenance 90 1.6 None Reactive maintenance at the present with 24h turn around time

Hour Logging, Pro-Active Maintenance and Servicing or

possible standby Aerator. Also investigate timer for low

flow periods

Mechanical Failure

13 Aerobic Zone Aerator Gearbox 16 Medium Reactive Maintenance 90 1.6 None Reactive maintenance at the present with 24h turn around time

Hour Logging, Pro-Active Maintenance and Servicing or

possible standby Aerator. Also investigate timer for low

flow periods

Process Failure






90 2 Low Operational Monitoring to determine sludge wasting Operational Monitoring as scheduled with process

adjustments at alert levels as necessary

Structural Failure

17 Clarifier Clarifier Structure 15 Medium Inspection of Structure 0 15 Medium Inspection must occur during cleaning, Cracks observed on outside. Inspect structure during cleaning, perform structural

investigation with report

Process Failure






90 2 Low Operational monitoring to occur to alert levels with corrective

actions as per Alert Level

Ensure Monitoring occurs as scheduled and incident

management protocol is followed

Mechanical Failure

20 Pumping Station Pumps 25 High Standby Pump Available but not in sump 25 18.75 Medium Standby pump on site but not installed in sump Investigate installation of standby pump in sum as part of

future upgrade

Electrical Failure

22 Chlorination

Store Room

Warning Lights

outside building 25 High Reactive Maintenance and No Standby Generator on Site 50 12.5 Low

Entire system will be replaced with Chlorine tablet system until

future upgrade is completed

Coordinate a new disinfection system with future upgrade

of works

23 Chlorination

Store Room Dosing Electronics 25 High Reactive Maintenance and No Standby Generator on Site 50 12.5 Low




of works

Structural Failure

24 Chlorination

Store Room

Store Room

Structure 25 High Inspection of Structure 50 12.5 Low




of works

Structural Failure

25 Maturation

Ponds

Structures across

river 16 Medium 0 16 Medium

Structure across river may have leakages in crossing, relining of 1st

pond currently (2012) underway

Construct new Maturation ponds closer to the WWTW as

part of upgrading of WWTW

Process Failure

26 Maturation

Ponds

Compliance





90 2 Low Compliance monitoring to occur to alert levels with corrective

actions as per Alert Level

Ensure Monitoring occurs as scheduled and incident


Structural Failure

27 Sludge Drying

Beds Bed Structures 24 Medium 0 24 Medium Contractor appointed to refurbish the beds All beds to be refurbished

Process Failure

28 Sludge Drying

Beds Filter Medium 15 Medium 0 15 Medium

Water does not filter through quick enough, Contractor appointed

to refurbish the beds

All beds to be refurbished, monitor speed of water

filtration after refurbishments are complete

General

29 General Telemetry at works 20 Medium 0 20 Medium Contractor appointed to upgrade entire telemetry network Monitor contractor performance and telemetry

performance after commissioning

25


Item no







works 20 Medium 0 20 Medium No security guard at the works.

Provide security guard and facilities as part of the future

upgrade

31 General Site Lighting 20 Medium 0 20 Medium Minimal site lighting Additional site lighting must be provided as part of future

upgrade

If these mitigation measures are implemented the overall risk classification of the works may be regarded as Medium and therefore motivates the upgrades currently in progress.

26


4.8 Gouda WWTW

The full risk matrix for the Gouda WWTW is included in Annexure C. The risk classified as Medium or High Risks are shown in table 4.11 below

Table 4.11 : Gouda WWTW : Medium to High Risk Items Item no




Electrical Failure

2 Pumping

Station Standby power Y 5 5 25 High

Process Failure


Mechanical Failure

5 Inlet Hand Raked Screens Y 5 3 15 Medium

Process Failure

1 Inlet Spetic tank influent

compliance Y 4 5 20 Medium

Process Failure

10 Primary Pond 1 Operational


11 Primary Pond 2 Operational


12 Secondary

Pond 3

Operational


13 Secondary

Pond 4

Operational


14 Secondary

Pond 5

Operational


15 Secondary

Pond 6 Compliance Monitoring Y 5 5 25 High

16 Evaporation

Ponds

Ground Water

Monitoring Wells Y 4 5 20 Medium

General



works Y 5 4 20 Medium


The risks mainly consist only of operational- and compliance monitoring as the ponds are oxidation ponds and do not have much mechanical equipment.

These risks however, can be mitigated by employing risk mitigation measures which are shown in table 4.12 below.

27


Table 4.12 : Gouda WWTW : Risk Mitigation Measures for Medium to High Risks

Item no



of any controls)

Existing controls


(%)

Residual Risk Score

Comment


improvement plan

Electrical

Failure

2 Pumping

Station

Standby

power 25 High - 0 25 High

No Standby

Power

generator

available on

site

A standby power

generator must

be provided for

the pumping

station

Process

Failure

4 Inlet Influent


Operational

monitoring

through

weekly testing

as there is no

effluent

outflow from

this

evaporation

pond system

90 2 Low

Operational

monitoring is

to occur to

operational

monitoring

alert level

Ensure

monitoring

occurs as

scheduled

Mechanical

Failure

5 Inlet Hand Raked

Screens 15 Medium

Permanent

Cleaning of

Screen

throughout

the day

90 1.5 None

Permanently

posted staff

clean hand

raked screen,

however low

screenings

volume due to

mechnical

screen at

Gouda Sewage

Pumping

Station

Clean Screen

Daily

Process

Failure

1 Inlet

Spetic tank

influent

compliance

20 Medium - 0 20 Medium

No monitoring

of farms septic

tank loadings

(e.g. COD, etc.)

Sampling of farm

septic tanks

inffluent must be

performed to

gauge impact on

process

Process

Failure

10 Primary

Pond 1

Operational


Operational

Monitoring

weekly

sampling with

monthly

audits by

independent

lab. (A.L.

Abbott)

90 2 Low

Operational

monitoring to

occur to alert

levels with

corrective

actions as per

Alert Level

Ensure

Monitoring

occurs as

scheduled and

incident

management

protocol is

followed,

investigate

feasibility of Mini

lab. On site

11 Primary

Pond 2

Operational


Operational

Monitoring

weekly

sampling with

monthly

audits by

independent

lab. (A.L.

Abbott)

90 2 Low

Operational

monitoring to

occur to alert

levels with

corrective

actions as per

Alert Level

Ensure

Monitoring

occurs as

scheduled and

incident

management

protocol is

followed,

investigate

feasibility of Mini

lab. On site

28


Item no



of any controls)

Existing controls


(%)

Residual Risk Score

Comment


improvement plan

12 Secondary

Pond 3

Operational


Operational

Monitoring

weekly

sampling with

monthly

audits by

independent

lab. (A.L.

Abbott)

90 2 Low

Operational

monitoring to

occur to alert

levels with

corrective

actions as per

Alert Level

Ensure

Monitoring

occurs as

scheduled and

incident

management

protocol is

followed,

investigate

feasibility of Mini

lab. On site

13 Secondary

Pond 4

Operational


Operational

Monitoring

weekly

sampling with

monthly

audits by

independent

lab. (A.L.

Abbott)

90 2 Low

Operational

monitoring to

occur to alert

levels with

corrective

actions as per

Alert Level

Ensure

Monitoring

occurs as

scheduled and

incident

management

protocol is

followed,

investigate

feasibility of Mini

lab. On site

14 Secondary

Pond 5

Operational


Operational

Monitoring

weekly

sampling with

monthly

audits by

independent

lab. (A.L.

Abbott)

90 2 Low

Operational

monitoring to

occur to alert

levels with

corrective

actions as per

Alert Level

Ensure

Monitoring

occurs as

scheduled and

incident

management

protocol is

followed,

investigate

feasibility of Mini

lab. On site

15 Secondary

Pond 6

Compliance

Monitoring 25 High

Compliance

Monitoring

weekly

sampling with

monthly

audits by

independent

lab. (A.L.

Abbott)

90 2.5 Low

Compliance

monitoring to

occur to alert

levels with

corrective

actions as per

Alert Level

Ensure

Monitoring

occurs as

scheduled and

incident

management

protocol is

followed,

investigate

feasibility of Mini

lab. On site

16 Evaporation

Ponds

Ground

Water

Monitoring

Wells

20 Medium

Operational

Monitoring

weekly

sampling with

monthly

audits by

independent

lab. (A.L.

Abbott)

90 2 Low

Operational

monitoring to

occur to alert

levels with

corrective

actions as per

Alert Level

Ensure

Monitoring

occurs as

scheduled and

incident

management

protocol is

followed,

investigate

feasibility of Mini

lab. On site

General

17 General Telemetry

at works 20 Medium 0 20 Medium

Contractor

appointed to

upgrade entire

telemetry

network

Monitor

contractor

performance and

telemetry

performance

after

commissioning

18 General

Security

Guard at

works

20 Medium 0 20 Medium

No security

guard at the

works.

Provide security

guard and

facilities as part

of the future

upgrade

29


Item no



of any controls)

Existing controls


(%)

Residual Risk Score

Comment


improvement plan

19 General Site Lighting 20 Medium 0 20 Medium Minimal site

lighting

Additional site

lighting must be

provided as part

of future

upgrade


5 CONTROL MEASUREMENTS

The municipality conducts operational control of the WWTW’s according to a comprehensive operational monitoring program, which meets the minimum requirement of DWA as stipulated in the Green Drop certification criteria. Sampling is done on a frequent basis by the treatment plant personnel at the various WWTW’s, and analysed in a well-equipped laboratory situated at the Paarl WWTW. The operational monitoring programme of Drakenstein Municipality is summarised in the table 5.1 below:

Table 5.1 : Drakenstein Municipality’s Operational Monitoring Programme

Industries (Monitoring Intervals) WWTWs (Monitoring Intervals)

Paarl Weekly Paarl Weekly, 24 hrs Tuesday to Wednesday. Final

effluent weekly

Wellington Two Weekly Wellington

Two Weekly, 24 hrs Wednesday to Thursday. Final effluent weekly

Smaller WWTW’s Final effluent twice per week

Industries (Analysis) WWTW’s (Analysis)

pH, Electrical Conductivity, COD, Phosphates See Table 5.2

WWTW’s Sampling Points

Paarl

Industrial raw inlet, Industrial raw settled, Domestic raw inlet, Domestic raw settled, Biofilters (5 sets) inlet and outlet, Humus settling tanks (5) outlet, Combined humus tank effluent (to activated sludge), Clarifiers (2) outlet, Maturation (aeration) pond, Final effluent to the Berg River (chlorinated), Activated sludge MLSS

Wellington Raw inlet, Raw inlet settled (3 Primary settling tanks), Biofilters (5 sets) inlet and outlet, Humus settling tanks (2) outlet, Clarifiers (2) outlet, Retention pond, Final effluent to the Berg River (chlorinated), Activated sludge MLSS

Pearl Valley Raw inlet, Clarifier, Final effluent, Activated sludge MLSS

Saron Raw inlet, Clarifier, Final effluent, Activated sludge MLSS

Gouda Oxidation ponds outlets (7)

Hermon Raw inlet, Final effluent

30


Table 5.2: Drakenstein Municipality’s Sample Analysis Details

WWTW Sampling point Frequency of

sampling Analyses performed on the samples

Paarl

Industrial raw inlet Weekly COD, pH, EC, tot.alk., settleable solids, ammonia, phosphate, Cd, Cr, Cu, Ni, Zn K, Na, Pb

Industrial raw settled Weekly COD, pH, EC, ammonia, phosphate

Domestic raw inlet Weekly COD, pH, EC, tot.alk., settleable solids, ammonia, phosphate, Cd, Cr, Cu, Ni, Zn K, Na, Pb

Domestic raw settled Weekly COD, pH, EC, ammonia, phosphate

Biofilters (5 sets) inlet and outlet)

Weekly COD, pH, EC

Humus settling tanks (5) outlet Weekly COD, pH, EC

Combined humus tank effluent (to activated sludge)

Weekly COD, pH, EC

Clarifiers (2) outlet Weekly COD, pH, EC

Maturation (aeration) pond Weekly COD, pH, EC, dissolved oxygen, temp, ammonia, phosphate

Final effluent to Berg river (chlorinated)

Daily COD, pH, EC, ammonia, tot.alk., dissolved oxygen, temp, Cl

-,

Cd, Cr, Cu, Ni, Zn K, Na, Pb, tot.Cl2

Activated sludge MLSS Daily suspended solids

Wellington

Raw inlet Daily COD, pH, EC, tot.alk., settleable solids, ammonia, phosphate, Cd, Cr, Cu, Ni, Zn K, Na, Pb

Raw inlet settled

(3 primary settling tanks) Weekly COD, pH, EC, tot.alk., ammonia, phosphate

Biofilters (5 sets) inlet and outlet

Weekly COD, pH, EC

Humus Settling tanks (2) outlet Weekly COD, pH, EC

Clarifiers (2) outlet Daily COD, pH, EC

Retention pond Weekly COD, pH, EC

Final effluent to Berg river (chlorinated)

Daily COD, pH, EC, ammonia, tot.alk., dissolved oxygen, temp, Cl

-,


Activated sludge MLSS Daily suspended solids

Pearl Valley

Raw inlet 2/week COD, pH, EC, ammonia, phosphate, Cd, Cr, Cu, Ni, Zn K, Na, Pb

Clarifier 2/week COD, pH, EC

Final effluent 2/week COD, pH, EC, ammonia, tot.alk., dissolved oxygen, temp, Cl-,


Activated sludge MLSS 2/week suspended solids

Saron

Raw inlet 2/week COD, pH, EC, tot.alk., ammonia, phosphate

Clarifier 2/week COD, pH, EC

Final effluent 2/week COD, pH, EC, ammonia, tot.alk., dissolved oxygen, temp, Cl-,


Activated sludge MLSS 2/week suspended solids

Gouda

Oxidation pond 1 raw 2/week COD, pH, EC, ammonia, phosphate, tot.alk

Oxidation pond 2 raw Weekly COD, pH, EC, ammonia, phosphate, tot.alk

Oxidation pond 3 outlet Weekly COD, pH, EC




Oxidation pond 7 outlet 2/week COD, pH, EC

Oxidation pond 8 (final effluent) COD, pH, EC, ammonia, tot.alk., dissolved oxygen, temp.

Hermon Raw inlet 2/week COD, pH, EC, ammonia, phosphate

Final effluent 2/week COD, pH, EC, ammonia, tot.alk., dissolved oxygen, temp.

The sampling (location; frequency) performed at the various treatment plants is in accordance with

the minimum requirements of the Green Drop programme of DWA.

The critical monitoring points for all the Activated Sludge WWTW’s is the discharge points from where problems in the process can be identified through the other monitoring points.

31


6 MONITORING OF CONTROL MEASURES AND RESPONSE PROTOCOL

The Drakenstein Municipality Wastewater Section has implemented an incident response protocol, in which certain reactive procedures are followed when an incident occurs (normally when a malfunction of the treatment processes occur due to power failures, faulty equipment, adverse weather conditions, human error, etc). There are two levels of incident management, firstly when a final effluent is discharged that does not meet the requirements of the Water Act, and secondly when an event takes place causing a major pollution event for which emergency response is required. Currently, these requirements are the General Standard for the Paarl, Wellington-, Pearl Valley- and Saron WWTW, and Irrigation Standards for the Gouda and Hermon Pond Systems. After the recent upgrading of the Paarl WWTW and upgrading of the Wellington WWTW in the near future, both of these plants will have to comply with the Special Standard for discharging into the Berg River. The Pearl Valley WWTW will also be required to meet the Special Standard requirements. A set of Compliance Alert Levels, corresponding to the requirements of the General Standard (at present), has been drawn up as part of a Wastewater Incident Management Protocol for Drakenstein Municipality, and is shown in the table 6.1 below. Table 6.1 : Compliance Alert Levels

Table 6.1: WWTW’s Compliance Alert Levels

Compliance Monitoring Sample

Alert Levels requiring action Response Protocol

Paarl WWTW

Final Effluent

COD > 75 mg/L

TSS > 25 mg/L

5.5 > pH > 9.5

EC > 150 mS/m

Ammonia > 6 mg/L as N

Nitrate > 15 mg/L as N

Ortho- P > 10 mg/L as P

Total Cl2 < 0.3 mg/L

E. Coli > 100 #/100 mL

Temp > 300 C

Cd > 0.005 mg/L

Cr > 0.05 mg/L

Cu > 0.01 mg/L

Zn > 0.1 mg/L

Pb > 0.01mg/L

Laboratory personnel to notify:

- Mr. Frans van Rooyen

- Mr. Cecil Paulse

- Mr. Cedric Morkel

Mr. Morkel to notify Mr. Brown, and then Response Protocol to be followed

Wellington WWTW

Final Effluent

COD > 75 mg/L

TSS > 25 mg/L

5.5 > pH > 9.5

EC > 150 mS/m



Ortho- P > 10 mg/L as P


E. Coli > 100 #/100 mL

Temp > 300 C

Cd > 0.005 mg/L

Cr > 0.05 mg/L

Cu > 0.01 mg/L

Zn > 0.1 mg/L

Pb > 0.01mg/L


- Mr. Adam van Wyk

- Mr. Cecil Paulse

- Mr. Cedric Morkel


Pearl Valley WWTW

Final Effluent

COD > 75 mg/L

TSS > 25 mg/L

5.5 > pH > 9.5

EC > 150 mS/m



Ortho- P > 10 mg/L as


E. Coli > 100 #/100 mL

Temp > 300 C

Cd > 0.005 mg/L

Cr > 0.05 mg/L

Cu > 0.01 mg/L

Zn > 0.1 mg/L

Pb > 0.01mg/L


- Mr. Shane Gardner

- Mr. Cecil Paulse

- Mr. Cedric Morkel


Saron WWTW

Final Effluent

COD > 75 mg/L

TSS > 25 mg/L

5.5 > pH > 9.5

EC > 150 mS/m



Ortho- P > 10 mg/L as


E. Coli > 100 #/100 mL

Temp > 300 C

Cd > 0.005 mg/L

Cr > 0.05 mg/L

Cu > 0.01 mg/L

Zn > 0.1 mg/L

Pb > 0.01mg/L


- Ms. Tanya Simons

- Mr. Cecil Paulse

- Mr. Cedric Morkel


When the Compliance Alert Levels are exceeded, the actions stipulated in the Wastewater Incident Management Protocol of the municipality are followed. The Protocol is included in Annexure D.

For serious incidents or emergency situations, additional actions and notifications are required, including notification of DWA and the media/public. The protocol to be followed in these situations is included in the Wastewater Incident Management Protocol.

32


6.1 Operational Alert Levels

For continuously improving the performance of the various WWTW’s, a set of operational alert levels has also been drawn up and followed by the operating personnel. The Operational Alert Levels are tabled below.

Table 6.2.1: WWTW’s Operational Alert Levels

ALL ACTIVATED SLUDGE WASTEWATER TREATMENT WORKS

(Paarl / Wellington / Pearl Valley / Saron)

Operational Samples Alert Levels Actions to be taken

Raw inlet

COD > 1000 mg/L


5.5 > pH > 9.5

EC > 150 mS/m

Settl. solids > 20 mL/L

Cd > 0.005 mg/L

Cr > 0.05 mg/L

Cu > 0.01 mg/L

Zn > 0.1 mg/L

Pb > 0.01 mg/L

• Check for possible illegal industrial effluent discharge

• Do more frequent measurements of DO levels, pH and MLSS in the activated sludge reactor

Raw inlet settled COD > 400 mg/L

• Check operation of PST (faulty scrapers; blockages)

• Check for oils and fats on the water surface

Activated sludge reactor

DO < 0.5 mg/L • Increase aeration capacity or cycles

MLSS < 2000 mg/L • Reduce discharge of WAS and allow MLSS –

levels to increase to 4000 mg/L

MLSS > 6000 mg/L • Gradually waste more sludge on a daily basis

to reduce the MLSS to 4000 mg/L

pH < 7.0

• Add lime to the inlet works to maintain the pH in the reactor at 7.0 or slightly above

Secondary settling tanks

COD > 75 mg/L

• Check for sludge carry – over from secondary settling tanks

• Check RAS recycle rates

• Check for bulking sludge

• Check for rising sludge

Take actions to rectify as appropriate

6.2 Verification of functioning of W2RAP

It is imperative that the functioning of the W2RAP can be monitored. If the W

2RAP is functioning

correctly there should be a decrease in risk and consequently better Wastewater treatment. There are various legislative requirements which will monitor the functioning of the W

2RAP indirectly,

such as the Green Drop Certification process and the RPMS system implemented by DWA. A well functioning W

2RAP will show improved scores in these processes.

Internal monitoring will also show improvement from well functioning W

2RAP. Comparisons of

internal monitoring results such as final effluent compliance over time will provide an indication of W

2RAP effectiveness.

Furthermore the W

2RAP is to be used inter alia with other Municipal Systems such as the Asset

Management Plan and the Operational and Maintenance Plans and the risk mitigation measures employed or identified in the W

2RAP must be aligned with these plans.

As stated above the W

2RAP must be reviewed at least once a year. A well functioning W

2RAP will

show a reduction in risk, year on year, due to implementation of mitigation measures.

33


7 SUPPORT PROGRAMMES

Drakenstein Municipality provides various training projects and supporting programmes to educate their staff.

7.1 Process Controller Training Provided

On request of the Engineer: Waste Services (Mr R Brown), an on-site short course in wastewater treatment was presented to the process controllers and plant managers of the Drakenstein Municipality Wastewater Section by Water Training Africa in association with Seboka Manyabolo Management Solutions. The three-day course was presented on 3-5 May 2010 at the Training Centre of the Drakenstein Municipality and included practical training on site at the Paarl, Wellington, Pearl Valley and Saron wastewater treatment plants.

The course covered all aspects of municipal wastewater treatment, with an emphasis on practical aspects, and monitoring requirements. Evaluation of the candidates was done by means of a written-test, and certificates were presented to the course attendees on completion of the course.

7.2 Supervisors Forum

Drakenstein Municipality in conjunction with the University of Stellenbosch have partnered with other Municipalities within the Western Cape to be part of a WWTW Supervisors forum, where supervisors come together for training events and knowledge sharing.

Through this initiative valuable knowledge and problems solving skills are imparted on WWTW Supervisors. This type of support will provide valuable knowledge for incident situations. 7.3 Career Pathing

Professor Lagardien of the Cape Peninsula University of Technology has been approached to perform a Human Capital Development Audit which will inform the Municipality on career pathing and training priorities for its staff. Through this initiative risks associated with staffing problems can be addressed.

7.4 Consultant Advisors

The Municipality currently also employs several consultants, such as AL Abbott Laboratories and Integral Laboratories, to assist the Municipality with process audits.

These consultants form an integral part of the monitoring and verification processes which unfortunately, the Municipality does not always have the capacity to perform at the moment. 8 INCIDENT MANAGEMENT PLAN

Drakenstein Municipality has implemented an Incident Management Protocol (Annexure D) for all of their WWTW. The protocol differentiates between three alert levels based on the severity of the incident. These alert levels are shown in figure 8.1 below.

34


Figure 8.1 Alert Levels and Reporting Implementation of these alert levels and the actions will occur as shown in the flowchart in figure 8.2 below.

Alert Level III:

Definite risk to health

or possible death

Inform : All stated for alert level two and Disaster and Emergency Management, Head of Department : Civil Engineering Services, Executive Director : Infrastructure and Planning, Municipal Manager, DWA, General PublicAction : As per protocol

Alert Level II:

Potential risk to health

Inform : Senior Laboratory Chemist, Process Controllers, Plant Supervisor, District Supervisor, Head of Waste Services

Action : As per protocol

Alert Level I :

No significant risk to health

Inform : Senior Laboratory Chemist, Process Controllers, Plant Supervisor

Action : As per protocol

35


Figure 8.2 Flow Chart of Incident Protocol

Incident

Senior Chemist or Process Controller : Report incident to Plant Supervisor

Plant Supervisor : Can Problem be Solved ?

Yes

Plant Supervisor to implement corrective action and report to District Supervisor

No

District Supervisor : Can Problem be Solved ?

Yes

District Supervisor to implement Incident Management Protocol and report to Head of Waste Services

No

Head of Waste Services: Can Problem be Solved ?

Yes

Head of Waste Services to implement Incident Management Protocol and report to Head of Department : Civil Engineering Services

No

Head of Waste Services to report and provide ongoing updates to :

Implement Incident Management Protocol

Disaster Management and Environmental Management

Head of Department : Civil Engineering Services

Executive Director : Infrastructure and Planning

Municipal Manager

Press, Public and DWA

Alert Level I

Alert Level II

Alert Level III

36


9 CONCLUSIONS

The Hazard- or Risk Assessments of the various works show that Drakenstein Municipality have or are implementing various methods which mitigate their risks in terms of wastewater treatment. Saron WWTW is the highest risk and is therefore currently upgraded. The next phase of the upgrade also needs to be implemented as a matter of urgency. Initiatives include various training programmes for staff as well as cooperative governance. Furthermore the municipality also has implemented various management plans which include Incident Management Protocols, Asset Management and Operation and Maintenance Plans. Various risks have been identified for each works and mitigation measures have been proposed.

10 RECOMMENDATIONS 10.1 Risks to be addressed

The various high to medium risk items which must be addressed are shown in Annexure E along with the proposed mitigation measures. The most urgent risks are those associated with the Saron- and Wellington WWTW’s of which emergency funding for Saron WWTW is being applied for and the Wellington WWTW upgrading is in the planning and EIA phase.

10.2 Way forward

Priority must be given to the high risk items at each WWTW and allocations must be made through either staffing, operation and maintenance- or capital project budgets. An internal W²RAP workshop with all WWTW staff must be conducted to familiarize them with the W²RAP and the principle of risk management A yearly review of the W²RAP must be scheduled. It is proposed that the W²RAP must be updated in February every year.


ANNEXURE A :

CATCHMENTS


ANNEXURE B :

FLOW DIAGRAMMES


ANNEXURE C :

DRAKENSTEIN MUNICIPALITY :

WWTW RISK ASSESSMENT

Item no Area Location System Hazard/Risk DescriptionCould this issue

result in a risk?Likelihood Consequence Existing controls Control reference

Control

Effectiveness

(%)

Comment Recommended mitigation/ improvement

planResponsibility Deadline Budget Signature

Electrical Failure

1 Pumping Station Pumps Y 2 2 4 Low2 Standby 1 Duty pumps , Daily pumping

Station inspection with checklist50 2 Low Reactive maintenance C Morkel Ongoing

2 Pumping Station Flow Meter Y 2 2 4 LowDaily pumping Station inspection with

checklist50 2 Low Reactive maintenance C Morkel Ongoing

3 Pumping Station Power Failure Y 2 2 4 Low Standby generator on site 90 0.4 NoneProactive maintenance and

servicing required for GeneratorC Morkel Ongoing

Mechanical Failure

4 Pumping Station Mechanical Screen Y 2 2 4 LowDaily pumping Station inspection with

checklist50 2 Low Reactive maintenance C Morkel Ongoing

5 Pumping Station Washer Compactor Y 1 2 2 LowDaily pumping Station inspection with

checklist50 1 None Reactive maintenance C Morkel Ongoing

Structural Failure

6 Pumping Station Structure Y 1 2 2 Low New Structure 90 0.2 NoneInspection of structure must occur

during cleaningC Morkel Ongoing

Electrical Failure

7 Domestic Pumping Station Failure of Pump MC Y 3 3 9 LowStandby Pumps installed & Standby

Generator- 100 0 None

Only becomes risk if O&M not applied or applied

lateMust follow O&M procedure C Morkel Ongoing

Mechanical Failure

8 Domestic Pumping Station Pump Failure Y 3 4 12 Low Standby Pumps installed - 50 6 Low

Long turnaround on pump repairs may cause risk

and unscreened sewage is pumped which may lead

to pump blockage

Time restriction on pump repair

for suppliers, installation of

mechanical screens must be

investigated during future upgrade

C Morkel & R Brown & Consultants Ongoing

9 Domestic Pumping Station Valve or sluice gate failure N 1 3 3 Low Gasket for all three pumps including standby - 100 0 None

Structural Failure

10 Domestic Pumping Station Pump station sump Y 1 5 5 LowPhysical inspection of the sump during

scheduled cleaning- 50 2.5 Low Visual inspection may not reveal all problems

Visual inspection of sump must be

recordedC Morkel Ongoing

Process Failure

11 Domestic Pumping Station Influent compliance Y 4 5 20 Medium Operational monitoring i.e Laboratory testing - 80 4 LowOperational monitoring is to occur to operational

monitoring alert level


scheduled

C Morkel

C PaulseOngoing

12 Domestic Pumping Station Design Capacity Y 4 5 20 Medium - - 0 20 MediumThe existing Pumping Station has a lower capacity

than newly constructed sewer


with higher capacityR Brown & Consultants 2016

Electrical Failure

13 Domestic Inlet Works Power failure Y 3 4 12 Low Standby generator on site - 100 0 None

14 Domestic Inlet Works Motor failure N 2 3 6 Low 2No so will be able to function with 1 100 0 None Backup grit removal mechanical screen and pumps

Mechanical Failure

15 Domestic Inlet Works Mechanical screen N 1 2 2 Low Standby screen available 100 0 None

16 Domestic Inlet Works Grit removal (Vortex) N 1 2 2 Low 2No so will be able to function with 1 100 0 None

17 Domestic Inlet Works Pumps N 2 3 6 Low Standby pump available 100 0 None

Structural Failure

18 Domestic Inlet Works Inlet works N 1 2 2 Low Structure is new 100 0 NoneVisual inspection with timing

determined by Asset RegisterR Brown TBC

Mechanical Failure

19 Industrial Inlet Works Hand Sluices Y 1 4 4 LowInspection of Sluices and Standby Stream

through daily inspections as per checklist80 0.8 None

Inspect and test permanently

closed sluices at least once a yearC Morkel Yearly

20 Industrial Inlet Works Hand Raked Screens Y 5 3 15 MediumPermanent Cleaning of Screen throughout

the day70 4.5 Low Permanently posted staff clean hand raked screen


mechanical screens in futureC Morkel & R Brown & Consultants 2016

Process Failure

21 Industrial Inlet Works Influent compliance Y 4 5 20 Medium Operational monitoring i.e Laboratory testing - 80 4 LowOperational monitoring is to occur to operational



scheduled

C Morkel

C PaulseOngoing

Structural Failure

HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : PAARL WWTW

Inherent Risk Score (before

consideration of any controls)Residual Risk Score

Pa

arl

WW

TW

Mb

ek

we

ni

Se

wa

ge

Pu

mp

ing

Sta

tio

nD

om

est

ic P

um

pin

g S

tati

on

Inle

t W

ork

s



Control

Effectiveness

(%)






22 Industrial Inlet Works Inlet Works Structure Y 1 5 5 Low Inspection of Structure 100 0 None Inspect Structure once a year C Morkel Yearly

Electrical Failure

23 Industrial Pumping Station Power failure Y 3 4 12 Low Standby generator on site - 100 0 None

24 Industrial Pumping Station Pump Motor's and MCC Y 2 4 8 LowReactive Maintenance, Standby Generator

and Standby Pump90 0.8 None

Pro-Active Maintenance and

ServicingC Morkel Ongoing

Mechanical Failure

25 Industrial Pumping Station Pumps Y 2 4 8 Low Reactive Maintenance Standby Pump 80 1.6 NonePro-Active Maintenance and


Structural Failure

26 Flocculator Flocculator Structure Y 3 3 9 Low Inspection of Structure 100 0 None Inspect Structure once a year C Morkel Yearly

Process Failure

27 Flocculator Operational Monitoring Y 4 4 16 MediumOperational Monitoring i.e Laboratory

testing80 3.2 Low

Operational monitoring to occur to alert levels with

corrective actions as per Alert Level




C Morkel

C PaulseOngoing

Electrical Failure

28 Flocculator Power failure to bridge Y 3 5 15 Medium - 0 15 MediumNo power to the bridge at present and process is

being affected


immediatelyC Morkel & R Brown End 2012

Mechanical Failure

29 Domestic splitterbox Sluice gates Y 1 5 5 Low Operation & Maintenance - 100 0 None Inspection must occur and sluices tested Test sluices at least once a year C Morkel Yearly

Structural Failure

30 Domestic splitterbox Tower Y 3 5 15 Medium - - 0 15 Medium Tower must be investigatedInvestigate structure of tower and

gratingsR Brown/Sub-consultants 2016

Electrical Failure

31 Domestic PST's Motor for Scum plate bridge Y 2 3 6 Low Operation & Maintenance - 50 3 Low Re-active maintenance at the moment Pro-active maintenanceR Brown

C Morkel2015

Structural Failure

32 Domestic PST's Structure Y 1 5 5 Low Inspection of structure - 50 2.5 LowOne of the PST's recently inspected and needed

refurbishment

Continual inspection during

mandatory shutdownC Morkel Ongoing

Process Failure

33 Domestic PST's Operational Monitoring Y 4 4 16 MediumOperational Monitoring i.e Laboratory

testing- 80 3.2 Low

Operational monitoring needed with Actions as per

Alert LevelFollow Alert Level actions

C Morkel

C PaulseOngoing

Electrical Failure

34 Biofilters Motor failure of Arms Y 1 3 3 Low Operation & Maintenance - 50 1.5 None Operational and Maintenance occurs reactivelyMotors to be serviced as per O&M

ManualC Morkel Ongoing

Mechanical Failure

35 Biofilters Splitter Tower Splitter tower sluice gates Y 1 4 4 Low Operation & Maintenance - 100 0 None Inspection must occur and sluices tested Test sluices at least once a year C Morkel Ongoing

Structural Failure

36 Biofilters Splitter Tower Tower Y 1 2 2 LowTower has been replaced as part of

upgrading100 0 None

The existing tower was replaced during upgrading

of WWTW

Inspection of new Tower once a

yearC Morkel Ongoing

Mechanical Failure

37 Biofilters Gearbox failure on biofilter arms Y 2 2 4 Low Operation & Maintenance 50 2 Low Operational and Maintenance occurs reactivelyInspections & maintenance to

occur pro-activelyC Morkel & Process Controllers Ongoing

Structural Failure

38 Biofilters Old Biofilter walls Y 5 5 25 High Structure strapping 10 22.5 Mediumcurrently strapping is used to reinforce broken

brickwork outer walls


upgradeR Brown & Consultants 2016

Process Failure

39 Biofilters Operational Monitoring Y 4 4 16 MediumOperational Monitoring i.e Laboratory

testing80 3.2 Low






C Morkel

C PaulseOngoing

Electrical Failure

40 Humus Tanks Motor on sludge release arms Y 2 3 6 Low Operation & Maintenance 50 3 Low Reactive Maintenance at the moment Pro-active Maintenance required C Morkel & R Brown Ongoing

Mechanical Failure

41 Humus Tanks Gearbox on sludge arms Y 1 2 2 Low Operation & Maintenance 50 1 None Reactive Maintenance at the moment Pro-active Maintenance required C Morkel & R Brown Ongoing

Pa

arl

WW

TW

Pri

ma

ry S

ett

lin

g T

an

ks

Bio

filt

ers

Bio

filt

ers

Hu

mu

s T

an

ks



Control

Effectiveness

(%)






Structural Failure

42 Humus Tanks Humus Tank Structure Y 1 4 4 Low Inspection during Cleaning 80 0.8 NoneDuring Cleaning operation an inspection of the

structure must occurInspections during cleaning C Morkel Ongoing

Process Failure

43 Humus Tanks Operational Monitoring Y 4 4 16 MediumOperational Monitoring i.e Laboratory

testing80 3.2 Low






C Morkel

C PaulseOngoing

Electrical Failure

44 Parshall Flume Ultrasonic Meter Y 1 4 4 Low Reactive Maintenance 80 0.8 NoneIf no Flow is measured, Mass Balance affected or

risk of overflowSpeedy Reactive Maintenance C Morkel Ongoing

45 Screw Pumps MCC Boards Y 1 2 2 Low Reactive Maintenance 80 0.4 None Standby Screw is available (recently upgraded) Speedy Reactive Maintenance C Morkel Ongoing

Mechanical Failure

46 Screw Pumps Gearboxes for screw pumps Y 1 2 2 Low Reactive Maintenance 80 0.4 None Standby Screw is available (recently upgraded) Speedy Reactive Maintenance C Morkel Ongoing

Structural Failure

47 Screw Pumps Pumping Station Structure Y 1 5 5 LowInspection of structure during screw

maintenance80 1 None

Pumping Station is new and need only be inspected

during servicing of screwsInspection during screw service C Morkel Ongoing

Electrical Failure

48 Anaerobic Zone Mixer Motors Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are new and therefor need little

maintenance at the present



Mechanical Failure

49 Anaerobic Zone Mixer Gearbox Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are new and therefor need little




Structural Failure

50 Anaerobic Zone Zone Structure Y 1 2 2 Low Inspection during sludge removal in future 100 0 NoneThe structure is newly constructed and will only

need inspection once it is cleaned in future

Inspection during sludge removal

in futureC Morkel Ongoing

Electrical Failure

51 Anoxic Zone Mixer Motors Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are new and therefor need little




52 Anoxic Zone Recycle Pump Motors and MCC Y 1 4 4 Low Reactive Maintenance 80 0.8 None The Pumps are new and need little maintenancePro-Active Maintenance and


Hu

mu

s T

an

ks

Scr

ew

Pu

mp

ing

Sta

tio

n



Control

Effectiveness

(%)






Mechanical Failure

53 Anoxic Zone Mixer Gearbox Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are new and therefor need little




54 Anoxic Zone Sludge Recycle Pumps Y 1 5 5 LowStandby Pump available and reactive

maintenance80 1 None Reactive Maintenance C Morkel Ongoing

Structural Failure

55 Anoxic Zone Zone Structure Y 1 2 2 Low Inspection during sludge removal in future 100 0 NoneThe structure is newly constructed and will only



in futureC Morkel Ongoing

Electrical Failure

56 Aerobic Zone Aerator Motors Y 3 4 12 Low Reactive Maintenance and Standby Aerators 80 2.4 LowFacility available for removal of aerator from pond

for repair

Hour Logging, Pro-Active

Maintenance and ServicingC Morkel & Process Controllers Ongoing

57 Aerobic Zone Sludge Recycle Pumps Y 1 5 5 LowStandby Pump available and reactive


Mechanical Failure

58 Aerobic Zone Aerator Gearbox Y 3 4 12 Low Reactive Maintenance and Standby Aerators 80 2.4 LowFacility available for removal of aerator from pond

for repair


Maintenance and ServicingC Morkel & Process Controllers Ongoing



Process Failure

60 Aerobic Zone Operational Monitoring Y 4 5 20 Medium Operational Monitoring 80 4 LowOperational Monitoring to determine sludge

wasting




necessary

C Morkel & C Paulse & R Brown Ongoing

Mechanical Failure

61 Clarifier Splitter Box Sluice gates Y 1 3 3 Low Operation & Maintenance 100 0 None Inspection must occur and sluices testedTest Sluice Gates at least once a

year.C Morkel Ongoing

Structural Failure

62 Clarifier Splitter Box Splitter Box Structure Y 1 5 5 Low Inspection of Structure 100 0 NoneInspection must occur during testing of sluices

tested

Inspect structure during sluice gate

serviceC Morkel Ongoing

Electrical Failure

63 Clarifier Scum Plate motors Y 1 5 5 Low Reactive Maintenance 80 1 NoneReactive Maintenance at present, however one of

the clarifiers is newly constructed

Pro-Active Maintenance Required

& servicingC Morkel Ongoing

Mechanical Failure

64 Clarifier Scum Plate Gearboxes or Roller Y 2 5 10 Low Reactive Maintenance 80 2 LowReactive Maintenance at present, however one of

the clarifiers is newly constructed


& servicingC Morkel Ongoing

Structural Failure

65 Clarifier Clarifier Structure Y 1 5 5 Low Inspection of Structure 100 0 None Inspection must occur during cleaning Inspect structure during cleaning C Morkel Ongoing

Process Failure

66 Clarifier Operational Monitoring Y 4 5 20 Medium Operational Monitoring 80 4 LowOperational monitoring to occur to alert levels with





C Morkel

C PaulseOngoing

Structural Failure

67 New Clarifier Clarifier Structure too low Y 4 4 16 Medium - 0 16 Medium

The clarifier structure was constructed low in the

ground and the possibility exists for someone to

fall into the clarifier as there is no handrail around

the clarifier

Construct handrail around clarifier

with apronR Brown & Consultants 2016

Electrical Failure

67 Recycle Pumping Station Pump Motor's and MCC Y 2 3 6 Low Standby Pump Available 100 0 NoneEnsure Standby pump is

operationalC Morkel & Process Controllers Ongoing

Mechanical Failure

68 Recycle Pumping Station Pumps Y 3 3 9 Low Standby Pump Available 100 0 NoneEnsure Standby pump is


Structural Failure

69 Recycle Pumping Station Pumping Station Structure Y 1 5 5 Low Inspection of Structure during cleaning 100 0 NoneTwo Pumping stations are available to allow

inspection of one while other is operationalInspect Structure during cleaning C Morkel Ongoing

Electrical Failure

70 Waste Pumping Station Pump Motor's and MCC Y 2 3 6 Low Standby Pump Available 100 0 NoneEnsure Standby pump is


Mechanical Failure

71 Waste Pumping Station Pumps Y 3 3 9 Low Standby Pump Available 100 0 NoneEnsure Standby pump is


Structural Failure

Pa

arl

WW

TW

Act

iva

ted

Slu

dg

e R

ea

cto

rC

lari

fie

rsR

ecy

cle

& W

ast

e S

lud

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Pu

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ing

Sta

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n



Control

Effectiveness

(%)






72 Waste Pumping Station Pumping Station Structure Y 1 5 5 Low Inspection of Structure during cleaning 100 0 NoneTwo Pumping stations are available to allow

inspection of one while other is operationalInspect Structure during cleaning C Morkel Ongoing

Electrical Failure

73 Belt Presses Belt Press Motors N 1 2 2 Low Reactive Maintenance 80 0.4 None 4 Belt Presses available Reactive Maintenance C Morkel Ongoing

74 Belt Presses Power failure N 1 2 2 Low Standby generator on site 80 0.4 None

Mechanical Failure

75 Belt Presses Belt Presses N 1 2 2 Low Reactive Maintenance 80 0.4 None 4 Belt Presses available Reactive Maintenance C Morkel Ongoing

Structural Failure

76 Dewatering Building Dewatering Building Structure Y 1 3 3 Low Inspection of Building 100 0 NoneBuilding is new and does not handle effluent, only

sludgeVisual inspection once a year C Morkel Ongoing

Structural Failure

77 Tanks Dome structure on Tanks Y 5 5 25 High Signage, Gas traps and 24h monitoring 80 5 Low

Inspection of the dome must occur

at regular interval as determined

by a structural Engineer

C Morkel & R Brown & Consultant Ongoing

Structural Failure

78 Digester Structure of digester Y 5 5 25 High Signage, Gas traps and 24h monitoring 80 5 Low

Inspection of the dome must occur

at regular interval as determined

by a structural Engineer


Mechanical Failure

79 Digester Mixer Motors Y 2 5 10 Low Reactive Maintenance 80 2 LowProactive maintenance & servicing

requiredC Morkel Ongoing

General

80 Digester Deep Structure Y 5 5 25 High - 0 25 HighNo life buoy or safety ropes in a very deep

structure

Provide life buoys and safety ropes

for structureC Morkel & R Brown & Consultant 2013

General

81 Incinerators Incinerators very old Y 4 4 16 Medium - 0 16 MediumThe incinerators are very old and parts have

become hard to source



upgrade

C Morkel & R Brown & Consultant 2016

General

82 Generator Nearing end of service life Y 2 5 10 Low - 0 10 Low

The generator are very old and parts have become

hard to source, however some new generators are

currently under contract to be installed.

Upgrade of the generator must be

investigated as part of future

upgrade.


Structural Failure

83 Maturation Ponds Pond Wall Breakage Y 1 6 6 Low Ponds below Ground 100 0 None

Process Failure

84 Maturation Ponds Operational Monitoring Y 4 5 20 Medium Operational Monitoring 80 4 LowOperational monitoring to occur to alert levels with





C Morkel

C PaulseOngoing

Electrical Failure

85 Chlorination Store Room Warning Lights outside building Y 4 6 24 MediumWarning lights checked daily, with Reactive

Maintenance and Standby Generator on Site100 0 None Weekly inspection of Component

C Morkel

C PaulseOngoing

86 Chlorination Store Room Dosing Electronics Y 4 6 24 MediumReactive Maintenance and Standby

Generator on Site80 4.8 Low Weekly inspection of Component

C Morkel

C PaulseOngoing

Structural Failure

87 Chlorination Store Room Store Room Structure Y 1 6 6 Low Inspection of Structure 100 0 None Inspect Structure once a Year C Morkel Yearly

Structural Failure

88 Chlorination Channel Channel Structure Y 1 5 5 Low Inspection of Structure 80 1 None Inspect Structure once a Year C Morkel Yearly

Process Failure

89 Chlorination Channel Compliance Monitoring Y 5 5 25 High24h Compliance Monitoring with on site lab.

Newly refurbished90 2.5 Low

Compliance Monitoring to occur to alert levels with





C Morkel

C Paulse & R BrownOngoing

General

90 Laboratory New Laboratory Chemical Room Y 1 2 2 LowNew chemical room with warning light and

extractor fans90 0.2 None -

Ensure all control measures are

checked on regular basis C Paulse & R BrownOngoing

Electrical Failure

91 Transformer Transformers on site (4 No) Y 5 5 25 HighOperation and Maintenance from

Drakenstein Electrical Department0 25 High

Drakenstein Electrical Department is laboring under

capacity constraints and maintenance cannot

always be effected in time



adhered to and additional staffing

in the Electrical Department

D du Plessis Ongoing

Lab

ora

tory

Ele

ctri

cal

Tra

nsf

orm

er

Pri

ma

ry G

as

Dig

est

ers

Se

con

da

ry G

as

Dig

est

er

Inci

ne

rato

rsG

en

era

tor

Ma

tura

tio

n P

on

ds

Ch

lori

na

tio

n

Pa

arl

WW

TW

De

wa

teri

ng

Fa

cili

tyM

eth

an

e T

an

ks



Control

Effectiveness

(%)






92

Ge

nse

t

Genset Switch Over Board Y 4 5 20 Medium - 0 20 MediumThe existing switch board is old and is in need of

upgrading with new switchgear, etc.


board as part of future upgrade of

works


General

93 General Security N 1 2 2 LowNew security fence installed and Security

provided at night95 0.1 None

Reactive Maintenance on fence

may be requiredC Morkel ongoing

94 General Site Lighting Y 3 5 15 Medium Existing high mast lighting 50 7.5 LowInvestigate additional high mast

lighting when requiredC Morkel & R Brown & Consultant 2016

95 General Telemetry at works Y 5 4 20 Medium 0 20 MediumContractor appointed to upgrade entire telemetry

network



commissioning

R Brown & Consultant 2013 R 700 k

96 General Signage Y 2 5 10 Low Existing signage on site 50 5 Low Additional Signage may be requireInvestigate additional signage as

part of future upgradeR Brown & Consultant 2016

Paarl

WWTW

Ge

ne

ral



Control

Effectiveness

(%)



Electrical Failure

1 Inlet Works Power failure Y 3 4 12 Low Standby generator on site - 100 0 None


risk of overflowSpeedy Reactive Maintenance M Krautz Ongoing

Mechanical Failure

3 Inlet Works Hand Sluices Y 1 4 4 Low Inspection of Sluices and Standby Stream 80 0.8 NoneInspect and test sluices once a

yearM Krautz Yearly

4 Inlet Works Hand Raked Screens Y 2 3 6 Low

Permanent Cleaning of Screen throughout

the day, daily inspection according to

checklists

90 0.6 None

Permanently posted staff clean hand raked screen,

low screenings volume from Pearl Valley and Val de

Vie. Not foreseen that mechanical screen is

required.

- M Krautz Ongoing

Process Failure

5 Inlet Works Influent compliance Y 2 5 10 Low

Operational Monitoring through on site Mini

Lab., weekly verification at Paarl WWTW lab.

and Monthly Audit by Independent Lab. (A.L.

Abbott)

- 80 2 Low

Operational monitoring is to occur to operational

monitoring alert level. However time sequencing

can be investigated due to low flow conditions at

times


scheduled

M Krautz & C Paulse & R Brown &

Consultants re time scheduling

Ongoing

Monitoring

& 2017 Time

Scheduling

Structural Failure

6 Inlet Works Inlet Works Structure Y 1 5 5 Low Inspection of Structure 100 0 None Inspect Structure once a year M Krautz Yearly

7 Splitter box Sluice gates Y 1 5 5 Low Operation & Maintenance - 100 0 None Inspection must occur and sluices tested Test sluices at least once a year M Krautz Yearly

Structural Failure

8 Splitter box Splitter Box Structure Y 1 5 5 Low Inspect Structure During Maintenance - 100 0 None Inspect Structure during Maintenance Investigate structure once a year M Krautz Yearly

Electrical Failure

9 Anaerobic Zone Mixer Motors Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are relatively new and therefore need

little maintenance at the present


ServicingM Krautz Ongoing

Mechanical Failure

10 Anaerobic Zone Mixer Gearbox Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are relatively new and therefore need




Structural Failure

11 Anaerobic Zone Zone Structure Y 1 2 2 Low Inspection during sludge removal in future 100 0 NoneThe structure is relatively new and will only need

inspection once it is cleaned in future


in futureM Krautz Ongoing

Electrical Failure

12 Anoxic Zone Mixer Motors Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are relatively new and therefore need




13 Anoxic Zone Recycle Pump Motors and MCC Y 1 4 4 LowStandby Pump available and reactive

maintenance80 0.8 None

The Pumps are relatively new and need little

maintenance



Mechanical Failure

14 Anoxic Zone Mixer Gearbox Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are relatively new and therefore need




15 Anoxic Zone Sludge Recycle Pumps Y 1 5 5 LowStandby Pump available and reactive



maintenance



Structural Failure

16 Anoxic Zone Zone Structure Y 1 2 2 Low Inspection during sludge removal in future 100 0 NoneThe structure is relatively new and will only need

inspection once it is cleaned in future


in futureM Krautz Ongoing

Electrical Failure

17 Aerobic Zone Aerator Motors Y 3 4 12 Low Reactive Maintenance and Standby Aerators 80 2.4 LowThe Aerators are relatively new and therefore need



Maintenance and ServicingM Krautz & Process Controllers Ongoing




maintenance



Mechanical Failure

19 Aerobic Zone Aerator Gearbox Y 3 4 12 Low Reactive Maintenance and Standby Aerators 80 2.4 LowThe Aerators are relatively new and therefore need



Maintenance and ServicingM Krautz & Process Controllers Ongoing




maintenance


& servicingM Krautz Ongoing

Process Failure

21 Aerobic Zone Operational Monitoring Y 2 5 10 Low




Abbott)

80 2 LowOperational Monitoring to determine sludge

wasting


scheduled with adjustments at

alert levels, add additional

monitoring to optimize process

M Krautz & C Paulse & R Brown Ongoing

Pe

arl

Va

lle

y W

WT

W

HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : PEARL VALLEY WWTW



Inle

t W

ork

sA

ctiv

ate

d S

lud

ge

Re

act

or

Act

iva

ted

Slu

dg

e R

ea

cto

rs



Control

Effectiveness

(%)






Electrical Failure

22 Clarifier Scum Plate motors Y 1 5 5 Low Reactive Maintenance 80 1 None Reactive Maintenance at presentPro-Active Maintenance Required


Mechanical Failure

23 Clarifier Scum Plate Gearboxes or Roller Y 2 5 10 Low Reactive Maintenance 80 2 Low Reactive Maintenance at presentPro-Active Maintenance Required


Structural Failure

24 Clarifier Clarifier Structure Y 1 5 5 Low Inspection of Structure 100 0 None Inspection must occur during cleaning Inspect structure during cleaning M Krautz Ongoing

Process Failure

25 Clarifier Operational Monitoring Y 2 5 10 Low




Abbott)

80 2 LowOperational monitoring to occur to alert levels with





M Krautz

C PaulseOngoing

Electrical Failure


operationalM Krautz & Process Controllers Ongoing

Mechanical Failure


operationalM Krautz & Process Controllers Ongoing

Structural Failure

28 Recycle Pumping Station Pumping Station Structure Y 1 5 5 Low Inspection of Structure during cleaning 100 0 None Inspect Structure during Maintenance Inspect Structure during cleaning M Krautz Ongoing

Electrical Failure

29 Belt Presses Belt Press Motors N 1 2 2 Low Reactive Maintenance 80 0.4 NoneMore than one Belt Presses available and low

sludge volumesReactive Maintenance M Krautz Ongoing

30 Belt Presses Power failure N 1 2 2 Low Standby generator on site 80 0.4 None

Mechanical Failure

31 Belt Presses Belt Presses N 1 2 2 Low Reactive Maintenance 80 0.4 NoneMore than one Belt Presses available and low

sludge volumesReactive Maintenance M Krautz Ongoing

Structural Failure

32 Dewatering Building Dewatering Building Structure Y 1 3 3 Low Inspection of Building 100 0 NoneBuilding is new and does not handle effluent, only

sludgeVisual inspection once a year M Krautz Ongoing

Electrical Failure

33 Chlorination Store Room Warning Lights outside building Y 4 6 24 MediumReactive Maintenance and Standby

Generator on Site80 4.8 Low

An audit has been performed and corrective

measures have been identified.Weekly inspection of Component

M Krautz

C Paulse & R Brown

Ongoing &

End 2012 for

Corrective

Measures





M Krautz

C Paulse

Ongoing &

End 2012 for

Corrective

Measures

Structural Failure

35 Chlorination Store Room Store Room Structure Y 1 6 6 Low Inspection of Structure 100 0 NoneAn audit has been performed and corrective

measures have been identified.Inspect Structure once a Year M Krautz Yearly

Structural Failure

36 Chlorination Channel Channel Structure Y 1 5 5 Low Inspection of Structure 80 1 NoneAn audit has been performed and corrective

measures have been identified.Inspect Structure once a Year M Krautz Yearly

Structural Failure


Process Failure


Compliance Monitoring through on site Mini



Abbott) and Maturation Pond Maintenance

80 5 Low

Compliance monitoring to occur to alert levels with

corrective actions as per Alert Level, Algal problems

occurred in retention pond and retention time was

reduced, however sediment transport remains

problematic




M Krautz

C PaulseOngoing

Mechanical Failure

39 Pumping Station Pumps Y 2 1 2 Low2 Pumps : 1 Duty 1 Standby and both new

pumps90 0.2 None -



40 Pumping Station Screening Basket Y 2 1 2 LowDaily inspection according to pumping

station checklist90 0.2 None Low screenings volume at the pumping station Daily inspections M Krautz Ongoing

Structural Failure

41 Pumping Station Pumping Station Structure Y 2 1 2 Low - 0 2 Low Structure is newInspection of structure during

cleaningM Krautz & R Brown & Consultants Ongoing

Se

wa

ge

Pu

mp

ing

Sta

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n

Pe

arl

Va

lle

y W

WT

W

De

wa

teri

ng

Fa

cili

tyM

atu

rati

on

Po

nd

sR

ecy

cle

Slu

dg

e P

um

pin

g S

tati

on

Ch

lori

na

tio

n



Control

Effectiveness

(%)






Electrical Failure

42 Pumping Station Power failure Y 5 4 20 Medium Standby generator on site & Overflow pond 90 2 Low -


& servicing of standby generator

required

M Krautz & R Brown Ongoing

43 Pumping Station Telemetry Y 4 5 20 Medium - 0 20 MediumContractor appointed to upgrade entire telemetry

network



commissioning

R Brown 2013

Mechanical Failure

44 Sludge Drying Beds Drainage Pump Y 4 4 16 Medium Reactive Maintenance 100 0 None New Pump Currently sourced

Monitor supplier performance and

pump performance after

commissioning

R Brown 2012

General

45 General Security at works Y 4 6 24 Medium - 0 24 Medium No Security on site

Provide security guard and

facilities as part of the future

upgrade

R Brown & Consultant 2016

46 General Office Facilities Y 5 6 30 High - 0 30 High No office on site. Non-Compliance with OSH ActProvide office facilities as part of

the future upgradeR Brown & Consultant 2016

Ge

ne

ral

Se

wa

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Pu

mp

ing

Sta

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n

Pe

arl

Va

lle

y W

WT

W

Slu

dg

e D

ryin

g

Be

ds



Control

Effectiveness

(%)



Electrical Failure

1 Pumping Station Power failure Y 5 5 25 High - 0 25 HighNo Standby Generator on site, Urgently required as

this is the closest pumping station to the Berg RiverProvide standby Generator to site R Brown & Consultant End 2013

Process Failure

2 Pumping Station Flow meter Y 3 5 15 Medium - 0 15 Medium Flow meter has not been commissioned Commission Flow meter R Brown & Consultant End 2013

Mechanical Failure

3 Pumping Station Screening of Sewage Y 4 5 20 MediumBasket screen, inspected daily according to

pumping station checklist90 2 Low -

Ensure inspections occur regularly

with cleaning as requiredD Claasens Ongoing

4 Pumping Station Pumps Y 2 5 10 Low

New pumps recently installed, reactive

maintenance by dedicated maintenance

team

90 1 None - Reactive Maintenance D Claasens Ongoing

Structural Failure

5 Pumping Station Structure Y 1 2 2 Low New Structure 90 0.2 None -Inspection of structure during

cleaningD Claasens Ongoing

General

6 Pumping Station No permanent supervision Y 5 5 25 High Daily inspections only 0 25 HighSupervision required as pumping station is closest

to Berg River

Investigate need for permanent

supervision on site or telemetry

system


7 Pumping Station Telemetry at pumping Station Y 2 3 6 Low - 0 6 Low

Telemetry required as pumping station is closest to

Berg River, Contractor appointed to upgrade entire

telemetry network



commissioning

R Brown 2013

Electrical Failure

8 Pumping Station Power failure Y 2 5 10 Low Standby Generator on site 90 1 None Standby Generator on siteProactive maintenance and

servicing required for GeneratorD Claasems Ongoing

Mechanical Failure

9 Pumping Station Screening of Sewage Y 2 5 10 LowMechanical Screens, inspected daily

according to pumping station checklist90 1 None -


with cleaning as required with

reactive maintenance for screens

D Claasens Ongoing

10 Pumping Station Pumps Y 2 5 10 Low4 Pumps with 3 Duty, inspected daily




reactive maintenance for Pumps

D Claasens Ongoing

Structural Failure



General

11 Pumping Station Security Y 5 5 25 High3m high wall with barbed wire, fencing,

security lights and Armed response80 5 Low

High vandalism rate at this pumping station forced

extreme security measures

Investigate inclusion of site into

perimeter of new fence around

WWTW and Land fill site


General

12 Pumping Station Design Capacity Exceedance Y 3 5 15 Medium - 0 15 Medium Capacity problems observed in past

Investigate capacity requirement

of this pumping station (currently

T3 pumps installed)


Electrical Failure

13 Pumping Station Power failure Y 2 5 10 Low Standby Generator on site 90 1 None Standby Generator on siteProactive maintenance and

servicing required for GeneratorD Claasems Ongoing

Mechanical Failure

14 Pumping Station Screening of Sewage Y 3 5 15 Medium - 0 15 MediumContract has been issued for provision of a

mechanical screen


and Mechanical Screen


R Brown & Consultant & D

ClaasensOngoing

15 Pumping Station Pumps Y 2 5 10 Low2 Pumps with 1 Duty, inspected daily




reactive maintenance for Pumps

D Claasens Ongoing

Structural Failure



General

17 Pumping Station Security Y 5 5 25 High Broken fencing and Armed response 25 18.75 MediumHigh vandalism rate at this pumping station

requires security measures

Investigate construction of new

fencing and possibly alarm systemR Brown & Consultant 2014

18 Pumping Station Telemetry at pumping Station Y 3 5 15 Medium - 0 15 Medium

Telemetry required as pumping station is closest to

Berg River, Contractor appointed to upgrade entire

telemetry network



commissioning

R Brown 2013

HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : WELLINGTON WWTW



We

llin

gto

n W

WT

W

Industrial Park

Sewage

Pumping

Station

(Pacmar)

Newton

Sewage

Pumping

Station

Erf 8000

Sewage

Pumping

Station



Control

Effectiveness

(%)






19

Pentz Street

Sewage

Pumping

Station

20

Wellington

Industries

Pumping

Station

General

21 General Plant Design Capacity Exceedance Y 5 5 25 High 0 25 HighUpgrading of Plant Required, All flows pumped to

WWTW therefor also may need a balancing dam

Upgrade entire Plant and

investigate the construction of

balancing dam to balance flows

from all the pumping stations

D Claasens & R Brown &

Consultants2016

Electrical Failure

22 Inlet Works Power failure Y 5 5 25 High No Standby Generator on site - 0 25 High No Standby Generator on SiteInstall Standby Generator as part

of upgrade


Consultants2016

23 Inlet Works Grit Remover (Vortex) Motor failure N 2 3 6 Low 2No so will be able to function with 1 50 3 Low Backup grit removal D Claasens Ongoing

Mechanical Failure

24 Inlet Works Grit removal (Vortex) Gearbox N 1 2 2 Low 2No so will be able to function with 1 100 0 None Backup grit removal D Claasens

Structural Failure

25 Inlet Works Inlet works N 1 4 4 Low Inspection of Structure 0 4 LowStructure is old but will be upgraded as part of

WWTW upgrade

Upgrade structure as part of

WWTW upgrade


Consultants2015

Process Failure





Abbott)

- 80 4 LowOperational monitoring is to occur to operational



scheduled

D Claasens

C PaulseOngoing

Mechanical Failure

27 Splitterbox Sluice gates Y 1 5 5 Low Operation & Maintenance - 100 0 None Inspection must occur and sluices tested Test sluices at least once a year D Claasens Yearly

Structural Failure

28 Splitterbox Structure Y 1 5 5 Low Inspection of Structure - 50 2.5 Low Inspection of Structure to determine condition Inspect Structure once a Year D Claasens Yearly

Electrical Failure

29 PST's Motor for Scum plate bridge Y 2 3 6 Low Operation & Maintenance - 50 3 Low Re-active maintenance at the moment Pro-active maintenanceR Brown

D Claasens2015

Structural Failure

30 PST's Structure Y 1 5 5 Low Inspection of structure - 50 2.5 LowOne of the PST's recently inspected and needed

refurbishmentInspect Structure once a Year D Claasens Yearly

Process Failure





Abbott)

- 80 3.2 LowOperational monitoring needed with Actions as per

Alert LevelFollow Alert Level actions

D Claasens

C PaulseOngoing

Mechanical Failure

33 Biofilters Splitter Tower Splitter tower sluice gates Y 1 4 4 Low Operation & Maintenance - 100 0 None Inspection must occur and sluices tested Test sluices at least once a year D Claasens Ongoing

Structural Failure

34 Biofilters Splitter Tower Tower Y 1 5 5 Low Inspection of structure 50 2.5 Low Inspection of Structure to determine condition Inspect Structure once a Year D Claasens Yearly

Electrical Failure

32 Biofilters Motor failure of Arms Y 1 3 3 Low Operation & Maintenance - 50 1.5 None Operational and Maintenance occurs reactivelyMotors to be serviced as per O&M

ManualD Claasens Ongoing

Mechanical Failure

35 Biofilters Gearbox failure on biofilter arms Y 2 2 4 Low Operation & Maintenance 50 2 Low Operational and Maintenance occurs reactivelyInspections & maintenance to

occur pro-activelyD Claasens & Process Controllers Ongoing

Structural Failure

36 Biofilters Biofilter Structure Y 1 5 5 Low Inspection of structure 50 2.5 Low Inspection of Structure to determine condition Inspect Structure once a Year D Claasens Yearly

Process Failure





Abbott)

80 3.2 LowOperational monitoring to occur to alert levels with





D Claasens

C PaulseOngoing

New Contract Out for Construction of a new Pumping Station at Pentz Street. A Full HAZOP was performed for the Pumping Station. Refer to HAZOP for Details

This Pumping Station is to be decommissioned and sewage will drain towards the new Pentz Street Pumping Station

We

llin

gto

n W

WT

W

Inle

t W

ork

sP

rim

ary

Se

ttli

ng

Ta

nk

sB

iofi

lte

rs



Control

Effectiveness

(%)






Mechanical Failure

38 Humus Tanks Splitter Box Splitter tower sluice gates Y 1 4 4 Low Operation & Maintenance - 100 0 None Inspection must occur and sluices tested Test sluices at least once a year D Claasens Yearly

Structural Failure

39 Humus Tanks Splitter Box Structure Y 1 5 5 Low Inspection of Structure - 50 2.5 Low Inspection of Structure to determine condition Inspect Structure once a Year D Claasens Yearly

Electrical Failure

40 Humus Tanks Motor on sludge release arms Y 2 3 6 Low Operation & Maintenance 50 3 Low Reactive Maintenance at the moment Pro-active Maintenance required D Claasens & R Brown Ongoing

Mechanical Failure

41 Humus Tanks Gearbox on sludge arms Y 1 2 2 Low Operation & Maintenance 50 1 None Reactive Maintenance at the moment Pro-active Maintenance required D Claasens & R Brown Ongoing

Structural Failure

42 Humus Tanks Humus Tank Structure Y 1 4 4 Low Inspection during Cleaning 80 0.8 NoneDuring Cleaning operation an inspection of the

structure must occurInspections during cleaning D Claasens Ongoing

Process Failure





Abbott)

80 3.2 LowOperational monitoring to occur to alert levels with





D Claasens

C PaulseOngoing

Electrical Failure


risk of overflowSpeedy Reactive Maintenance D Claasens Ongoing

45 Humus Effluent Pumps Motor's and MCC Boards Y 2 3 6 Low Reactive Maintenance 80 1.2 None Standby Pumps available Speedy Reactive Maintenance D Claasens Ongoing

Mechanical Failure

46 Humus Effluent Pumps Pumps Y 1 2 2 Low Reactive Maintenance 80 0.4 None Standby Pumps available Speedy Reactive Maintenance D Claasens Ongoing

Structural Failure

47 Humus Effluent Pumps Pumping Station Structure Y 1 5 5 LowInspection of structure during screw


Pumping Station must be inspected during servicing

of pumpsInspection during Pump service D Claasens Ongoing

Electrical Failure

48 Anoxic Zone Mixer Motors Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are new and therefor need little



ServicingD Claasens Ongoing

Mechanical Failure

49 Anoxic Zone Mixer Gearbox Y 2 4 8 Low Reactive Maintenance 80 1.6 NoneThe Mixers are new and therefor need little



ServicingD Claasens Ongoing

Structural Failure

50 Anoxic Zone Zone Structure Y 1 2 2 Low Inspection during sludge removal in future 100 0 NoneThe structure is newly constructed and will only



in futureD Claasens Ongoing

Electrical Failure

51 Aerobic Zone Aerator Motors Y 3 4 12 Low Reactive Maintenance and Standby Aerators 80 2.4 LowFixed aerator on pedestal so able to remove

aerator from pond for repair


Maintenance and ServicingD Claasens & Process Controllers Ongoing


maintenance80 1 None Reactive Maintenance D Claasens Ongoing

Mechanical Failure

53 Aerobic Zone Aerator Gearbox Y 3 4 12 Low Reactive Maintenance and Standby Aerators 80 2.4 LowFixed aerator on pedestal so able to remove

aerator from pond for repair


Maintenance and ServicingD Claasens & Process Controllers Ongoing


maintenance80 1 None Reactive Maintenance D Claasens Ongoing

Process Failure





Abbott)


wasting




necessary

D Claasens & C Paulse & R Brown Ongoing

Electrical Failure

56 Clarifier Scum Plate motors Y 1 5 5 Low Reactive Maintenance 80 1 None Reactive Maintenance at presentPro-Active Maintenance Required

& servicingD Claasens Ongoing

Hu

mu

s T

an

ks

We

llin

gto

n W

WT

W

Hu

mu

s T

an

ks

Hu

mu

s T

an

k E

fflu

en

t P

um

pin

g S

tati

on

Act

iva

ted

Slu

dg

e R

ea

cto

r



Control

Effectiveness

(%)






Mechanical Failure

57 Clarifier Scum Plate Gearboxes or Roller Y 2 5 10 Low Reactive Maintenance 80 2 Low Reactive Maintenance at presentPro-Active Maintenance Required

& servicingD Claasens Ongoing

Structural Failure

58 Clarifier Clarifier Structure Y 1 5 5 Low Inspection of Structure 100 0 None Inspection must occur during cleaning Inspect structure during cleaning D Claasens Ongoing

Process Failure





Abbott)






D Claasens

C PaulseOngoing

Electrical Failure


operationalD Claasens & Process Controllers Ongoing

Mechanical Failure



Structural Failure

62 Recycle Pumping Station Pumping Station Structure Y 1 5 5 Low Inspection of Structure during cleaning 100 0 None Inspect Structure during Maintenance Inspect Structure during cleaning D Claasens Ongoing

Electrical Failure

63 Waste Pumping Station Pump Motor's and MCC Y 2 3 6 Low Standby Pump Available 100 0 NoneEnsure Standby pump is


Mechanical Failure

64 Waste Pumping Station Pumps Y 3 3 9 Low Standby Pump Available 100 0 NoneEnsure Standby pump is


Structural Failure

65 Waste Pumping Station Pumping Station Structure Y 1 5 5 Low Inspection of Structure during cleaning 100 0 None Inspect Structure during Maintenance Inspect Structure during cleaning D Claasens Ongoing

Electrical Failure

66 Chlorination Store Room Warning Lights outside building Y 5 5 25 High

Reactive Maintenance and No Standby

Generator on Site, Inspection completed and

Certificate for compliance obtained

90 2.5 Low A Standby Generator on site is imperative

Weekly inspection of Component

and installation of Standby

Generator on site

D Claasens

C Paulse & R Brown & Consultants2015

67 Chlorination Store Room Dosing Electronics Y 5 5 25 High


Generator on Site, Inspection completed and

Certificate for compliance obtained




Generator on site

D Claasens


Structural Failure

68 Chlorination Store Room Store Room Structure Y 1 6 6 Low Inspection of Structure 100 0 None Inspect Structure once a Year D Claasens Yearly

Structural Failure


Process Failure





Abbott)

80 5 LowCompliance monitoring to occur to alert levels with





D Claasens

C PaulseOngoing

General

71 Sludge Drying Beds Design Capacity Exceedance Y 5 5 25 High - 0 25 High2 Waste ponds, Large Sludge Volume coming into

works.

Investigate sludge handling (e.g.

Dewatering Plant) as part of future

upgrade of works


Consultants2016

General

72 Digester No Gas Tank Y 4 5 20 Medium - 0 20 Medium

The plant has Gas Digesters but no gas tank. A

waste to energy project has been initiated which

could utilize the gas

Investigate gas storage or

conveyance to waste to energy site

as part of future upgrade of works


Consultants2016

General

73 Incinerator No incinerator on site for screenings Y 4 5 20 MediumScreenings conveyed to Paarl WWTW for

Incineration50 10 Low -

Investigate on site incinerators or

conveyance to waste to energy site

as part of future upgrade of works


Consultants2016

We

llin

gto

n W

WT

W

Re

cycl

e &

Wa

ste

Slu

dg

e P

um

pin

g S

tati

on

Ch

lori

na

tio

nM

atu

rati

on

Po

nd

sS

lud

ge

Dry

ing

Be

ds

Ga

s D

ige

ste

rIn

cin

era

tor



Control

Effectiveness

(%)






General

74 Personnel Facilities Offices Y 4 5 20 MediumSome office space provided with limited

ablution facilities10 18 Medium Existing facilities do not comply with OSH Act

Investigate the construction of a

new office building with ablution

facilities all to comply with the

OSH Act as part of future upgrade

of works


Consultants2016


network



commissioning

R Brown 2013

76 General Site Lighting Y 5 4 20 Medium Existing Lighting on site 50 10 Low Site lighting may be insufficient

Investigate the new or additional

high mast site lighting as part of

future upgrade of works


Consultants2016

77 General Security Y 5 5 25 High Existing Fence 25 18.75 MediumContract for a new security fence has been issued

and is underway


and maintain new fence after

commissioning


ConsultantsEnd 2012

78 General Signage Y 5 5 25 High - 0 25 HighSignage is required on site to comply with various

statutory regulations including the OSH Act

Investigate provision signage as

part of future upgradeR Brown & Consultant End 2013

Ge

ne

ral

DATE : 29-Jun-12 Rev B



Control

Effectiveness

(%)



Process Failure

1 Inlet Influent compliance Y 4 5 20 MediumOperational monitoring i.e. Laboratory

testing- 80 4 Low




scheduled

C Morkel

C PaulseOngoing

Structural Failure

2 Inlet Works Inlet Works Structure Y 1 5 5 Low Inspection of Structure 100 0 None Inspect Structure once a year C Morkel Yearly

Structural Failure

3 Evaporation pond 1 Pond Wall Breakage Y 1 6 6 Low Ponds below Ground 100 0 None



Process Failure

6 Evaporation pond 3 Operational Monitoring Y 4 5 20 Medium

Operational Monitoring weekly sampling

with monthly audits by independent lab.

(A.L. Abbott)

90 2 LowOperational monitoring to occur to alert levels

with corrective actions as per Alert Level



management protocol is followed,

Investigate need for Mini Lab. On

site

C Morkel


7 Evaporation Ponds Ground Water Monitoring Wells Y 4 5 20 Medium



(A.L. Abbott)






C Morkel

C PaulseOngoing

Structural Failure

8 Sump Structure Sump Structure Size Y 3 5 15 MediumDaily inspection of sump according to

Pumping Station checklist25 11.25 Low

Current sump structure to large and has overflow

walls and no Mechanical screen. Screenings

accumulate in first chamber and must be manually

removed

Investigate upgrade of pumping

station and installation of

Mechanical Screen

R Brown & Consultants 2017

Mechanical Failure

9 Pumps Pump Failure Y 3 5 15 MediumReactive maintenance with 24h turn around

time50 7.5 Low

Pumps may experience problems due to

screenings clogging the pumps

In the interm continue daily

inspections and Investigate

upgrade of pumping station and

installation of Mechanical Screen

in future

C Morkel & R Brown &

Consultants

Ongoing &

2017

Electrical Failure

10 Pumps No Standby Power Y 5 5 25 High - 0 25 HighAt the moment no Standby Power at the pumping

station

Investigate supply of standby

power generator at pumping

station


Consultants2017

General

11 General Telemetry at Pumpung Station Y 5 4 20 Medium 0 20 MediumContractor appointed to upgrade entire telemetry

network



commissioning

R Brown 2013 R 700 k

HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : HERMON WWTW



He

rmo

n S

ew

ag

e P

um

pin

g S

tati

on

He

rmo

n W

WT

W

Residual Risk Score

Ev

ap

ora

tio

n P

on

ds

Inle

t




Control

Effectiveness

(%)



Electrical Failure

1 Inlet Works Power failure Y 5 5 25 High No Standby generator on site - 0 25 High No Standby Generator on site

Install Standby Generator as part

of WWTW upgrade. Contractor

appointed and supply of generator

imminent

T Simons & R Brown & Consultant End 2012 R 350 k

2 Inlet Works Flow Meter failure Y 5 2 10 Low No Standby generator on site - 0 10 Low No Standby Generator on site



appointed and supply of generator

imminent

T Simons & R Brown & Consultant End 2012 N/A

Mechanical Failure

3 Inlet Works Hand Sluices Y 1 4 4 Low Inspection of Sluices and Standby Stream 80 0.8 None Daily inspections of sluices occur T Simons Daily N/A

4 Inlet Works Hand Raked Screens Y 5 3 15 MediumPermanent Cleaning of Screen throughout

the day70 4.5 Low

Permanently posted staff clean hand raked screen

and a new Mechanical screen will be provided at

the Saron Sewage pumping station in new contract

Monitor screenings amount after

commissioning of mechanical

screen at Saron Sewage pumping

station

T Simons & R Brown & ConsultantsEnd 2012

and OngoingN/A


risk of overflowSpeedy Reactive Maintenance T Simons Ongoing

Process Failure





Abbott)




scheduled

T Simons

C PaulseOngoing

7 Inlet Works Design Capacity N 4 5 20 Medium 0 20 Medium Upgrade needed of inlet worksUpgrade inlet Works as part of

WWTW upgradeT Simons & R Brown & Consultant 2014

Structural Failure

8 Inlet Works Inlet Works Structure Y 3 5 15 Medium Inspection of Structure 0 15 Medium Upgrade needed of inlet worksUpgrade inlet Works as part of


Electrical Failure

9 Anaerobic Zone Mixer Motors Y 4 4 16 Medium Reactive Maintenance 90 1.6 NoneReactive maintenance at the present with 24h turn

around time

Replaced Mixer and now Pro-

Active Maintenance and ServicingT Simons & C Morkel & R Brown Ongoing

Mechanical Failure

10 Anaerobic Zone Mixer Gearbox Y 4 4 16 Medium Reactive Maintenance 90 1.6 NoneReactive maintenance at the present with 24h turn

around time



Structural Failure

11 Anaerobic Zone Zone Structure Y 4 4 16 Medium 0 16 MediumNew Reactor must be constructed as part of

WWTW upgrade

Construct new Reactor as part of


Electrical Failure

12 Aerobic Zone Aerator Motors Y 4 4 16 Medium Reactive Maintenance 90 1.6 NoneReactive maintenance at the present with 24h turn

around time


Maintenance and Servicing or

possible standby Aerator. Also

investigate timer for low flow

periods

T Simons & Process Controllers & R

BrownOngoing

Mechanical Failure

13 Aerobic Zone Aerator Gearbox Y 4 4 16 Medium Reactive Maintenance 90 1.6 NoneReactive maintenance at the present with 24h turn

around time





periods

T Simons & Process Controllers & R

BrownOngoing

Process Failure





Abbott)


wasting




necessary

T Simons & C Paulse & R Brown Ongoing

Electrical Failure

15 Clarifier Bridge motors Y 1 5 5 Low Reactive Maintenance 80 1 NoneReactive maintenance at the present with 24h turn

around time


& servicingT Simons & C Morkel & R Brown Ongoing

Mechanical Failure

16 Clarifier Bridge Gearboxes or Roller Y 2 5 10 Low Reactive Maintenance 80 2 LowReactive maintenance at the present with 24h turn

around time


& servicingT Simons & C Morkel & R Brown Ongoing

Structural Failure

17 Clarifier Clarifier Structure Y 3 5 15 Medium Inspection of Structure 0 15 MediumInspection must occur during cleaning, Cracks

observed on outside.

Inspect structure during cleaning,

perform structural investigation

with report

T Simons & C Morkel & R Brown &

Consultants2016

Process Failure





Abbott)






T Simons

C PaulseOngoing

Electrical Failure

19 Pumping Station Pump Motor's and MCC Y 2 3 6 Low Standby Pump Available but not in sump 25 4.5 Low Standby pump on site but not installed in sump

Investigate installation of standby

pump in sum as part of future

upgrade


Consultants2016

HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : SARON WWTW



Sa

ron

WW

TW

Residual Risk Score

Inle

t W

ork

sR

ecy

cle

& W

ast

e S

lud

ge

Pu

mp

ing

Sta

tio

nA

ctiv

ate

d S

lud

ge

Re

act

or

Cla

rifi

er




Control

Effectiveness

(%)






Mechanical Failure

20 Pumping Station Pumps Y 5 5 25 High Standby Pump Available but not in sump 25 18.75 Medium Standby pump on site but not installed in sump



upgrade


Consultants2016

Structural Failure

21 Pumping Station Pumping Station Structure Y 1 5 5 Low Inspection of Structure during cleaning 100 0 None Inspect Structure during cleaning T Simons Ongoing

Electrical Failure

22 Chlorination Store Room Warning Lights outside building Y 5 5 25 HighReactive Maintenance and No Standby


Entire system will be replaced with Chlorine tablet

system until future upgrade is completed

Coordinate a new disinfection

system with future upgrade of

works

T Simons & R Brown & Consultant 2016

23 Chlorination Store Room Dosing Electronics Y 5 5 25 HighReactive Maintenance and No Standby






works


Structural Failure

24 Chlorination Store Room Store Room Structure Y 5 5 25 High Inspection of Structure 50 12.5 LowEntire system will be replaced with Chlorine tablet




works


Structural Failure

25 Maturation Ponds Structures across river Y 4 4 16 Medium 0 16 Medium

Structure across river may have leakages in

crossing, relining of 1st pond currently (2012)

underway

Construct new Maturation ponds

closer to the WWTW as part of

upgrading of WWTW


Process Failure

26 Maturation Ponds Compliance Monitoring Y 4 5 20 Medium




Abbott)

90 2 LowCompliance monitoring to occur to alert levels with





T Simons

C PaulseOngoing

Structural Failure

27 Sludge Drying Beds Bed Structures Y 4 6 24 Medium 0 24 Medium Contractor appointed to refurbish the beds All beds to be refurbished T Simons & R Brown & Consultant 2016

Process Failure

28 Sludge Drying Beds Filter Medium Y 5 3 15 Medium 0 15 MediumWater does not filter through quick enough,

Contractor appointed to refurbish the beds

All beds to be refurbished, monitor

speed of water filtration after

refurbishments are complete


General


network



commissioning


30 General Security Guard at works Y 5 4 20 Medium 0 20 Medium No security guard at the works.



upgrade


31 General Site Lighting Y 5 4 20 Medium 0 20 Medium Minimal site lightingAdditional site lighting must be

provided as part of future upgradeR Brown & Consultant 2016

Sa

ron

WW

TW

Slu

dg

e D

ryin

g B

ed

sG

en

era

lM

atu

rati

on

Po

nd

sC

hlo

rin

ati

on

Re

cycl

e &

Wa

ste

Slu

dg

e

Pu

mp

ing

Sta

tio

n

Re

cycl

e &

Wa

ste

Slu

dg

e

Pu

mp

ing

Sta

tio

n




Control

Effectiveness (%)Comment

Recommended mitigation/ improvement


Mechanical Failure

1 Pumping Station Pump Failure Y 1 2 2 Low2 No. Standby pumps with Mechanical

Screen90 0.2 None

Reactive Maintenance only with 24h turn around

time

Ensure standby pumps remain

opperationalR Jacobs Ongoing

Electrical Failure

2 Pumping Station Standby power Y 5 5 25 High - 0 25 High No Standby Power generator available on site

A standby power generator must

be provided for the pumping

station

R Brown 2016

Structural Failure

3 Pumping Station Pumping Station Structure Y 1 5 5 LowDaily Inspection of Structure from Pumping

Station inspection checklist90 0.5 None

Ensure Daily inspections occur

through spot checkingR Jacobs & C Morkel & R Brown Ongoing

Process Failure


Operational monitoring through weekly

testing as there no effluent outflow from this

evaporation pond system




scheduled

R Jacobs

C PaulseOngoing

Mechanical Failure

5 Inlet Hand Raked Screens Y 5 3 15 MediumPermanent Cleaning of Screen throughout

the day90 1.5 None


however low screenings volume due to mechnical

screen at Gouda Sewage Pumping Station

Clean Screen Daily R Jacobs Ongoing

Structural Failure

6 Inlet Works Inlet Works Structure Y 1 5 5 LowDaily Inspection of Structure from WWTW

inspection checklist100 0 None Continue with daily inspections R Jacobs & C Morkel Ongoing

Process Failure

1 Inlet Spetic tank influent compliance Y 4 5 20 Medium - - 0 20 MediumNo monitoring of farms septic tank loadings (e.g.

COD, etc.)

Sampling of farm septic tanks

inffluent must be performed to

gauge impact on process

R Jacobs & C Paulse & R Brown Ongoing

Structural Failure

7 Primary Ponds 1 & 2 Pond Wall Breakage Y 1 6 6 LowDaily inspection according to inspection

checklist & Ponds below Ground60 2.4 Low

Contractor appointed to constuct Gabion

protection

Monitor Daily after Gabion

protection has been constructedR Jacobs Ongoing

8 Secondary Ponds 3 to 6 Pond Wall Breakage Y 1 6 6 LowDaily inspection according to inspection

checklist & Ponds below Ground60 2.4 Low

Contractor appointed to constuct Gabion

protection

Monitor Daily after Gabion

protection has been constructedR Jacobs Ongoing

9 All Ponds Inlet and outlet structures to all ponds Y 1 4 4 LowDaily Inspection of Structures according to

inspection checklist100 0 None The structures were recently constructed Inspect all structures daily C Morkel Weekly

Process Failure

10 Primary Pond 1 Operational Monitoring Y 4 5 20 Medium



(A.L. Abbott)






investigate feasibility of Mini lab.

On site

C Morkel

C PaulseOngoing




(A.L. Abbott)







On site

C Morkel

C PaulseOngoing

12 Secondary Pond 3 Operational Monitoring Y 4 5 20 Medium



(A.L. Abbott)







On site

C Morkel

C PaulseOngoing




(A.L. Abbott)







On site

C Morkel

C PaulseOngoing




(A.L. Abbott)







On site

C Morkel

C PaulseOngoing

15 Secondary Pond 6 Compliance Monitoring Y 5 5 25 High

Compliance Monitoring weekly sampling


(A.L. Abbott)

90 2.5 LowCompliance monitoring to occur to alert levels with






On site

C Morkel

C PaulseOngoing




(A.L. Abbott)







On site

C Morkel

C PaulseOngoing

General


network



commissioning





upgrade




HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : GOUDA WWTW



Inle

tG

en

era

l

Go

ud

a W

WT

W

Residual Risk Score

Eva

po

rati

on

Po

nd

sG

ou

da

Se

wa

ge

Pu

mp

ing

Sta

tio

n


ANNEXURE D :

DRAKENSTEIN MUNICIPALITY :

WASTE WATER INCIDENT MANAGEMENT PROTOCOL


ANNEXURE E :

HIGH AND MEDIUM RISK ITEMS FOR WWTW

WITH MITIGATION MEASURES



Control

Effectiveness

(%)



Process Failure

11 Domestic Pumping Station Influent compliance Y 4 5 20 Medium


Lab., weekly verification at Paarl WWTW

lab. and Monthly Audit by Independent Lab.

(A.L. Abbott)




scheduled

C Morkel

C PaulseOngoing

12 Domestic Pumping Station Design Capacity Y 4 5 20 Medium - - 0 20 MediumThe existing Pumping Station has a lower capacity

than newly constructed sewer


with higher capacityR Brown & Consultants 2016

Mechanical Failure

20 Industrial Inlet Works Hand Raked Screens Y 5 3 15 MediumPermanent Cleaning of Screen throughout

the day70 4.5 Low Permanently posted staff clean hand raked screen


mechanical screens in future


Consultants2016

Process Failure

21 Industrial Inlet Works Influent compliance Y 4 5 20 Medium




(A.L. Abbott)




scheduled

C Morkel

C PaulseOngoing

Process Failure

27 Flocculator Operational Monitoring Y 4 4 16 Medium




(A.L. Abbott)

80 3.2 LowOperational monitoring to occur to alert levels





C Morkel

C PaulseOngoing

Electrical Failure

28 Flocculator Power failure to bridge Y 3 5 15 Medium - 0 15 MediumNo power to the bridge at present and process is

being affected


immediatelyC Morkel & R Brown End 2012

Structural Failure

30 Domestic splitterbox Tower Y 3 5 15 Medium - - 0 15 Medium Tower must be investigatedInvestigate structure of tower and

gratingsR Brown/Sub-consultants 2016

Process Failure

33 Domestic PST's Operational Monitoring Y 4 4 16 Medium




(A.L. Abbott)

- 80 3.2 LowOperational monitoring needed with Actions as

per Alert LevelFollow Alert Level actions

C Morkel

C PaulseOngoing

Structural Failure

38 Biofilters Old Biofilter walls Y 5 5 25 High Structure strapping 10 22.5 Mediumcurrently strapping is used to reinforce broken

brickwork outer walls


upgradeR Brown & Consultants 2016

Process Failure





(A.L. Abbott)






C Morkel

C PaulseOngoing

Process Failure





(A.L. Abbott)






C Morkel

C PaulseOngoing

Process Failure





(A.L. Abbott)


wasting




necessary

C Morkel & C Paulse & R Brown Ongoing

Process Failure





(A.L. Abbott)






C Morkel

C PaulseOngoing

Structural Failure

67 New Clarifier Clarifier Structure too low Y 4 4 16 Medium - 0 16 Medium

The clarifier structure was constructed low in the

ground and the possibility exists for someone to

fall into the clarifier as there is no handrail around

the clarifier

Construct handrail around clarifier

with apronR Brown & Consultants 2016

Structural Failure

77 Tanks Dome structure on Tanks Y 5 5 25 High Signage, Gas traps and 24h monitoring 80 5 Low




Engineer


Structural Failure

78 Digester Structure of digester Y 5 5 25 High Signage, Gas traps and 24h monitoring 80 5 Low




Engineer


General

80 Digester Deep Structure Y 5 5 25 High - 0 25 HighNo life buoy or safety ropes in a very deep

structure

Provide life buoys and safety

ropes for structureC Morkel & R Brown & Consultant 2013

General

81 Incinerators Incinerators very old Y 4 4 16 Medium - 0 16 MediumThe incinerators are very old and parts have

become hard to source



upgrade


Process Failure

84 Maturation Ponds Operational Monitoring Y 4 5 20 Medium




(A.L. Abbott)






C Morkel

C PaulseOngoing

Pri

ma

ry G

as

Dig

est

ers

Se

con

da

ry G

as

Dig

est

er

Inci

ne

rato

rsM

atu

rati

on

Po

nd

s

Pa

arl

WW

TW

Act

iva

ted

Slu

dg

e R

ea

cto

rC

lari

fie

rs

Pa

arl

WW

TW

Me

tha

ne

Ta

nk

s




Pa

arl

WW

TW Do

me

stic

Pu

mp

ing

Sta

tio

nIn

let

Wo

rks

Pa

arl

WW

TW

Pri

ma

ry S

ett

lin

g T

an

ks

Bio

filt

ers

Hu

mu

s T

an

ks



Control

Effectiveness

(%)






Electrical Failure

85 Chlorination Store Room Warning Lights outside building Y 4 6 24 MediumWarning lights checked daily, with Reactive

Maintenance and Standby Generator on Site100 0 None Weekly inspection of Component

C Morkel

C PaulseOngoing


Generator on Site80 4.8 Low Weekly inspection of Component

C Morkel

C PaulseOngoing

Process Failure

89 Chlorination Channel Compliance Monitoring Y 5 5 25 High24h Compliance Monitoring with on site lab.

Newly refurbished90 2.5 Low

Compliance Monitoring to occur to alert levels





C Morkel


Electrical Failure

91 Transformer Transformers on site (4 No) Y 5 5 25 HighOperation and Maintenance from

Drakenstein Electrical Department0 25 High

Drakenstein Electrical Department is laboring

under capacity constraints and maintenance

cannot always be effected in time



adhered to and additional staffing

in the Electrical Department

D du Plessis Ongoing

92

Ge

nse

t

Genset Switch Over Board Y 4 5 20 Medium - 0 20 MediumThe existing switch board is old and is in need of

upgrading with new switchgear, etc.


board as part of future upgrade of

works


General

94 General Site Lighting Y 3 5 15 Medium Existing high mast lighting 50 7.5 LowInvestigate additional high mast

lighting when requiredC Morkel & R Brown & Consultant 2016


network



commissioning

R Brown & Consultant 2013 R 700 k

Paarl

WWTW

Ele

ctri

cal

Tra

nsf

orm

er

Ge

ne

ral

Ch

lori

na

tio

n



Control

Effectiveness

(%)



Electrical Failure

33 Chlorination Store Room Warning Lights outside building Y 4 6 24 MediumReactive Maintenance and Standby




M Krautz

C Paulse & R Brown

Ongoing &

End 2012 for

Corrective

Measures





M Krautz

C Paulse

Ongoing &

End 2012 for

Corrective

Measures

Process Failure





(A.L. Abbott) and Maturation Pond

Maintenance

80 5 Low

Compliance monitoring to occur to alert levels

with corrective actions as per Alert Level, Algal

problems occurred in retention pond and

retention time was reduced, however sediment

transport remains problematic




M Krautz

C PaulseOngoing

Electrical Failure

42 Pumping Station Power failure Y 5 4 20 Medium Standby generator on site & Overflow pond 90 2 Low -


& servicing of standby generator

required

M Krautz & R Brown Ongoing

43 Pumping Station Telemetry Y 4 5 20 Medium - 0 20 MediumContractor appointed to upgrade entire telemetry

network



commissioning

R Brown 2013

Mechanical Failure

44 Sludge Drying Beds Drainage Pump Y 4 4 16 Medium Reactive Maintenance 100 0 None New Pump Currently sourced

Monitor supplier performance

and pump performance after

commissioning

R Brown 2012

General

45 General Security at works Y 4 6 24 Medium - 0 24 Medium No Security on site



upgrade


46 General Office Facilities Y 5 6 30 High - 0 30 High No office on site. Non-Compliance with OSH ActProvide office facilities as part of

the future upgradeR Brown & Consultant 2016

Pe

arl

Va

lle

y W

WT

W

Se

wa

ge

Pu

mp

ing

Sta

tio

nS

lud

ge

Dry

ing

Be

ds

Ge

ne

ral

Pe

arl

Va

lle

y W

WT

W

Ch

lori

na

tio

nM

atu

rati

on

Po

nd

s






Control

Effectiveness

(%)



Electrical Failure

1 Pumping Station Power failure Y 5 5 25 High - 0 25 High

No Standby Generator on site, Urgently required

as this is the closest pumping station to the Berg

River

Provide standby Generator to site R Brown & Consultant End 2013

Process Failure

2 Pumping Station Flow meter Y 3 5 15 Medium - 0 15 Medium Flow meter has not been commissioned Commission Flow meter R Brown & Consultant End 2013

Mechanical Failure

3 Pumping Station Screening of Sewage Y 4 5 20 MediumBasket screen, inspected daily according to

pumping station checklist90 2 Low -


with cleaning as requiredD Claasens Ongoing

General

6 Pumping Station No permanent supervision Y 5 5 25 High Daily inspections only 0 25 HighSupervision required as pumping station is closest

to Berg River

Investigate need for permanent

supervision on site or telemetry

system


General

11 Pumping Station Security Y 5 5 25 High3m high wall with barbed wire, fencing,

security lights and Armed response80 5 Low

High vandalism rate at this pumping station forced

extreme security measures

Investigate inclusion of site into

perimeter of new fence around

WWTW and Land fill site


General

12 Pumping Station Design Capacity Exceedance Y 3 5 15 Medium - 0 15 Medium Capacity problems observed in past

Investigate capacity requirement

of this pumping station (currently

T3 pumps installed)


Mechanical Failure

14 Pumping Station Screening of Sewage Y 3 5 15 Medium - 0 15 MediumContract has been issued for provision of a

mechanical screen


and Mechanical Screen


R Brown & Consultant & D

ClaasensOngoing

General

17 Pumping Station Security Y 5 5 25 High Broken fencing and Armed response 25 18.75 MediumHigh vandalism rate at this pumping station

requires security measures

Investigate construction of new

fencing and possibly alarm systemR Brown & Consultant 2014

18 Pumping Station Telemetry at pumping Station Y 3 5 15 Medium - 0 15 Medium

Telemetry required as pumping station is closest

to Berg River, Contractor appointed to upgrade

entire telemetry network



commissioning

R Brown 2013

General

21 General Plant Design Capacity Exceedance Y 5 5 25 High 0 25 HighUpgrading of Plant Required, All flows pumped to

WWTW therefor also may need a balancing dam

Upgrade entire Plant and

investigate the construction of

balancing dam to balance flows

from all the pumping stations


Consultants2016

Electrical Failure

22 Inlet Works Power failure Y 5 5 25 High No Standby Generator on site - 0 25 High No Standby Generator on SiteInstall Standby Generator as part

of upgrade


Consultants2016

Process Failure





(A.L. Abbott)




scheduled

D Claasens

C PaulseOngoing

Process Failure





(A.L. Abbott)

- 80 3.2 LowOperational monitoring needed with Actions as

per Alert LevelFollow Alert Level actions

D Claasens

C PaulseOngoing

Process Failure





(A.L. Abbott)






D Claasens

C PaulseOngoing

Process Failure





(A.L. Abbott)






D Claasens

C PaulseOngoing

Process Failure





(A.L. Abbott)


wasting




necessary

D Claasens & C Paulse & R Brown Ongoing

Process Failure





(A.L. Abbott)






D Claasens

C PaulseOngoing

Electrical Failure

66 Chlorination Store Room Warning Lights outside building Y 5 5 25 High


Generator on Site, Inspection completed

and Certificate for compliance obtained




Generator on site

D Claasens


67 Chlorination Store Room Dosing Electronics Y 5 5 25 High


Generator on Site, Inspection completed

and Certificate for compliance obtained




Generator on site

D Claasens





We

llin

gto

n W

WT

W

Industrial Park

Sewage

Pumping

Station

(Pacmar)

Newton

Sewage

Pumping

Station

Erf 8000

Sewage

Pumping

Station

We

llin

gto

n W

WT

W

Inle

t W

ork

sP

rim

ary

Se

ttli

ng

Ta

nk

sB

iofi

lte

rsC

hlo

rin

ati

on

We

llin

gto

n W

WT

W

Hu

mu

s T

an

ks

Act

iva

ted

Slu

dg

e R

ea

cto

r



Control

Effectiveness

(%)






Process Failure





(A.L. Abbott)

80 5 LowCompliance monitoring to occur to alert levels





D Claasens

C PaulseOngoing

General

71 Sludge Drying Beds Design Capacity Exceedance Y 5 5 25 High - 0 25 High2 Waste ponds, Large Sludge Volume coming into

works.

Investigate sludge handling (e.g.

Dewatering Plant) as part of



Consultants2016

General

72 Digester No Gas Tank Y 4 5 20 Medium - 0 20 Medium

The plant has Gas Digesters but no gas tank. A

waste to energy project has been initiated which

could utilize the gas

Investigate gas storage or

conveyance to waste to energy

site as part of future upgrade of

works


Consultants2016

General

73 Incinerator No incinerator on site for screenings Y 4 5 20 MediumScreenings conveyed to Paarl WWTW for

Incineration50 10 Low -

Investigate on site incinerators or

conveyance to waste to energy

site as part of future upgrade of

works


Consultants2016

General

74 Personnel Facilities Offices Y 4 5 20 MediumSome office space provided with limited

ablution facilities10 18 Medium Existing facilities do not comply with OSH Act

Investigate the construction of a

new office building with ablution

facilities all to comply with the

OSH Act as part of future upgrade

of works


Consultants2016


network



commissioning

R Brown 2013

76 General Site Lighting Y 5 4 20 Medium Existing Lighting on site 50 10 Low Site lighting may be insufficient

Investigate the new or additional

high mast site lighting as part of



Consultants2016

77 General Security Y 5 5 25 High Existing Fence 25 18.75 MediumContract for a new security fence has been issued

and is underway


and maintain new fence after

commissioning


ConsultantsEnd 2012

78 General Signage Y 5 5 25 High - 0 25 HighSignage is required on site to comply with various

statutory regulations including the OSH Act

Investigate provision signage as

part of future upgradeR Brown & Consultant End 2013

We

llin

gto

n W

WT

W

Ma

tura

tio

n

Po

nd

s

Slu

dg

e D

ryin

g

Be

ds

Ga

s D

ige

ste

rIn

cin

era

tor

Ge

ne

ral




Control

Effectiveness

(%)



Process Failure

1 Inlet Influent compliance Y 4 5 20 MediumOperational monitoring i.e. Laboratory

testing- 80 4 Low




scheduled

C Morkel

C PaulseOngoing

Process Failure

6 Evaporation pond 3 Operational Monitoring Y 4 5 20 Medium



(A.L. Abbott)






Investigate need for Mini Lab. On

site

C Morkel





(A.L. Abbott)






C Morkel

C PaulseOngoing

Structural Failure

8 Sump Structure Sump Structure Size Y 3 5 15 MediumDaily inspection of sump according to

Pumping Station checklist25 11.25 Low

Current sump structure to large and has overflow

walls and no Mechanical screen. Screenings

accumulate in first chamber and must be manually

removed

Investigate upgrade of pumping

station and installation of

Mechanical Screen

R Brown & Consultants 2017

Mechanical Failure

9 Pumps Pump Failure Y 3 5 15 MediumReactive maintenance with 24h turn around

time50 7.5 Low

Pumps may experience problems due to

screenings clogging the pumps

In the interm continue daily

inspections and Investigate

upgrade of pumping station and

installation of Mechanical Screen

in future


Consultants

Ongoing &

2017

Electrical Failure

10 Pumps No Standby Power Y 5 5 25 High - 0 25 HighAt the moment no Standby Power at the pumping

station

Investigate supply of standby

power generator at pumping

station


Consultants2017

General

11 General Telemetry at Pumping Station Y 5 4 20 Medium 0 20 MediumContractor appointed to upgrade entire telemetry

network



commissioning


HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : HERMON WWTW



He

rmo

n W

WT

W

Inle

tE

va

po

rati

on

Po

nd

sH

erm

on

Se

wa

ge

Pu

mp

ing

Sta

tio

n




Control

Effectiveness

(%)



Electrical Failure

1 Inlet Works Power failure Y 5 5 25 High No Standby generator on site - 0 25 High No Standby Generator on site



appointed and supply of

generator imminent

T Simons & R Brown & Consultant End 2012 R 350 k

Mechanical Failure

4 Inlet Works Hand Raked Screens Y 5 3 15 MediumPermanent Cleaning of Screen throughout

the day70 4.5 Low

Permanently posted staff clean hand raked screen

and a new Mechanical screen will be provided at

the Saron Sewage pumping station in new

contract

Monitor screenings amount after

commissioning of mechanical

screen at Saron Sewage pumping

station

T Simons & R Brown & ConsultantsEnd 2012

and OngoingN/A

Process Failure





(A.L. Abbott)




scheduled

T Simons

C PaulseOngoing

7 Inlet Works Design Capacity N 4 5 20 Medium 0 20 Medium Upgrade needed of inlet worksUpgrade inlet Works as part of


Structural Failure

8 Inlet Works Inlet Works Structure Y 3 5 15 Medium Inspection of Structure 0 15 Medium Upgrade needed of inlet worksUpgrade inlet Works as part of


Electrical Failure

9 Anaerobic Zone Mixer Motors Y 4 4 16 Medium Reactive Maintenance 90 1.6 NoneReactive maintenance at the present with 24h

turn around time



Mechanical Failure

10 Anaerobic Zone Mixer Gearbox Y 4 4 16 Medium Reactive Maintenance 90 1.6 NoneReactive maintenance at the present with 24h

turn around time



Structural Failure

11 Anaerobic Zone Zone Structure Y 4 4 16 Medium 0 16 MediumNew Reactor must be constructed as part of

WWTW upgrade

Construct new Reactor as part of


Electrical Failure

12 Aerobic Zone Aerator Motors Y 4 4 16 Medium Reactive Maintenance 90 1.6 NoneReactive maintenance at the present with 24h

turn around time





periods

T Simons & Process Controllers &

R BrownOngoing

Mechanical Failure

13 Aerobic Zone Aerator Gearbox Y 4 4 16 Medium Reactive Maintenance 90 1.6 NoneReactive maintenance at the present with 24h

turn around time





periods

T Simons & Process Controllers &

R BrownOngoing

Process Failure





(A.L. Abbott)


wasting




necessary

T Simons & C Paulse & R Brown Ongoing

Structural Failure

17 Clarifier Clarifier Structure Y 3 5 15 Medium Inspection of Structure 0 15 MediumInspection must occur during cleaning, Cracks

observed on outside.

Inspect structure during cleaning,

perform structural investigation

with report


Consultants2016

Process Failure





(A.L. Abbott)






T Simons

C PaulseOngoing

Mechanical Failure

20 Pumping Station Pumps Y 5 5 25 High Standby Pump Available but not in sump 25 18.75 Medium Standby pump on site but not installed in sump



upgrade


Consultants2016




Sa

ron

WW

TW

Inle

t W

ork

sA

ctiv

ate

d S

lud

ge

Re

act

or

Cla

rifi

er

Re

cycl

e &

Wa

ste

Slu

dg

e

Pu

mp

ing

Sta

tio

n




Control

Effectiveness

(%)






Electrical Failure

22 Chlorination Store Room Warning Lights outside building Y 5 5 25 HighReactive Maintenance and No Standby






works


23 Chlorination Store Room Dosing Electronics Y 5 5 25 HighReactive Maintenance and No Standby






works


Structural Failure

24 Chlorination Store Room Store Room Structure Y 5 5 25 High Inspection of Structure 50 12.5 LowEntire system will be replaced with Chlorine tablet




works


Structural Failure

25 Maturation Ponds Structures across river Y 4 4 16 Medium 0 16 Medium

Structure across river may have leakages in

crossing, relining of 1st pond currently (2012)

underway

Construct new Maturation ponds

closer to the WWTW as part of

upgrading of WWTW


Process Failure

26 Maturation Ponds Compliance Monitoring Y 4 5 20 Medium




(A.L. Abbott)

90 2 LowCompliance monitoring to occur to alert levels





T Simons

C PaulseOngoing

Structural Failure

27 Sludge Drying Beds Bed Structures Y 4 6 24 Medium 0 24 Medium Contractor appointed to refurbish the beds All beds to be refurbished T Simons & R Brown & Consultant 2016

Process Failure

28 Sludge Drying Beds Filter Medium Y 5 3 15 Medium 0 15 MediumWater does not filter through quick enough,

Contractor appointed to refurbish the beds

All beds to be refurbished,

monitor speed of water filtration

after refurbishments are complete


General


network



commissioning





upgrade




Sa

ron

WW

TW

Ch

lori

na

tio

nM

atu

rati

on

Po

nd

sS

lud

ge

Dry

ing

Be

ds

Ge

ne

ral




Control

Effectiveness (%)Comment

Recommended mitigation/ improvement


Electrical Failure

2 Pumping Station Standby power Y 5 5 25 High - 0 25 High No Standby Power generator available on site

A standby power generator must

be provided for the pumping

station

R Brown 2016

Process Failure


Operational monitoring through weekly

testing as there no effluent outflow from

this evaporation pond system




scheduled

R Jacobs

C PaulseOngoing

Mechanical Failure

5 Inlet Hand Raked Screens Y 5 3 15 MediumPermanent Cleaning of Screen throughout

the day90 1.5 None


however low screenings volume due to mechnical

screen at Gouda Sewage Pumping Station

Clean Screen Daily R Jacobs Ongoing

Process Failure

1 Inlet Spetic tank influent compliance Y 4 5 20 Medium - - 0 20 MediumNo monitoring of farms septic tank loadings (e.g.

COD, etc.)

Sampling of farm septic tanks

inffluent must be performed to

gauge impact on process

R Jacobs & C Paulse & R Brown Ongoing

Process Failure




(A.L. Abbott)







On site

C Morkel

C PaulseOngoing




(A.L. Abbott)







On site

C Morkel

C PaulseOngoing




(A.L. Abbott)







On site

C Morkel

C PaulseOngoing




(A.L. Abbott)







On site

C Morkel

C PaulseOngoing




(A.L. Abbott)







On site

C Morkel

C PaulseOngoing

15 Secondary Pond 6 Compliance Monitoring Y 5 5 25 High

Compliance Monitoring weekly sampling


(A.L. Abbott)

90 2.5 LowCompliance monitoring to occur to alert levels






On site

C Morkel

C PaulseOngoing




(A.L. Abbott)







On site

C Morkel

C PaulseOngoing

General


network



commissioning





upgrade




HAZARD ASSESSMENT DRAKENSTEIN MUNICIPAL WWTW'S : GOUDA WWTW



Go

ud

a S

ew

ag

e

Pu

mp

ing

Sta

tio

n

Go

ud

a W

WT

W

Inle

tE

va

po

rati

on

Po

nd

sG

en

era

l

drakenstein municipality - fewlbnexus.uct.ac.za · drakenstein municipality waste water risk...

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